diff --git a/.github/workflows/root-ci-config/buildconfig/alma10-clang_ninja.txt b/.github/workflows/root-ci-config/buildconfig/alma10-clang_ninja.txt
index f570304443ab1..acadc83443430 100644
--- a/.github/workflows/root-ci-config/buildconfig/alma10-clang_ninja.txt
+++ b/.github/workflows/root-ci-config/buildconfig/alma10-clang_ninja.txt
@@ -1,6 +1,7 @@
 CMAKE_C_COMPILER=clang
 CMAKE_CXX_COMPILER=clang++
 CMAKE_GENERATOR=Ninja
+builtin_fftw3=ON
 builtin_freetype=ON
 builtin_ftgl=ON
 builtin_gif=ON
diff --git a/builtins/fftw3/CMakeLists.txt b/builtins/fftw3/CMakeLists.txt
new file mode 100644
index 0000000000000..3f6f18abafa7e
--- /dev/null
+++ b/builtins/fftw3/CMakeLists.txt
@@ -0,0 +1,30 @@
+set(ROOT_FFTW_VERSION 3.3.10)
+message(STATUS "Downloading and building FFTW version ${ROOT_FFTW_VERSION}")
+set(ROOT_FFTW_PREFIX ${CMAKE_BINARY_DIR}/builtins/FFTW3-prefix)
+set(ROOT_FFTW_LIBRARY ${ROOT_FFTW_PREFIX}/lib/libfftw3.a)
+ExternalProject_Add(
+    BUILTIN_FFTW3
+    PREFIX ${ROOT_FFTW_PREFIX}
+    URL ${lcgpackages}/fftw-${ROOT_FFTW_VERSION}.tar.gz
+    URL_HASH SHA256=56c932549852cddcfafdab3820b0200c7742675be92179e59e6215b340e26467
+    CONFIGURE_COMMAND ./configure --prefix=<INSTALL_DIR>
+    BUILD_COMMAND make CFLAGS=-fPIC
+    LOG_DOWNLOAD 1 LOG_CONFIGURE 1 LOG_BUILD 1 LOG_INSTALL 1 LOG_OUTPUT_ON_FAILURE 1
+    BUILD_IN_SOURCE 1
+    BUILD_BYPRODUCTS ${ROOT_FFTW_LIBRARY}
+    TIMEOUT 600
+)
+
+set(ROOT_FFTW_INCLUDE_DIR ${ROOT_FFTW_PREFIX}/include)
+
+file(MAKE_DIRECTORY ${ROOT_FFTW_INCLUDE_DIR})
+add_library(FFTW::Double IMPORTED STATIC GLOBAL)
+add_dependencies(FFTW::Double BUILTIN_FFTW3)
+set_target_properties(FFTW::Double PROPERTIES
+    IMPORTED_LOCATION ${ROOT_FFTW_LIBRARY}
+    INTERFACE_INCLUDE_DIRECTORIES ${ROOT_FFTW_INCLUDE_DIR})
+
+set(FFTW_INCLUDE_DIRS ${ROOT_FFTW_INCLUDE_DIR} PARENT_SCOPE)
+set(FFTW_FOUND ON PARENT_SCOPE)
+set(FFTW_VERSION ${ROOT_FFTW_VERSION} PARENT_SCOPE)
+set(FFTW_LIBRARIES ${ROOT_FFTW_LIBRARY} PARENT_SCOPE)
diff --git a/cmake/modules/FindFFTW.cmake b/cmake/modules/FindFFTW.cmake
index 343d27b89fb7c..e74637a52013f 100644
--- a/cmake/modules/FindFFTW.cmake
+++ b/cmake/modules/FindFFTW.cmake
@@ -1,48 +1,448 @@
-# Copyright (C) 1995-2019, Rene Brun and Fons Rademakers.
-# All rights reserved.
+# - Find the FFTW library
+# https://github.com/egpbos/findFFTW/
+# Original version of this file:
+#   Copyright (c) 2015, Wenzel Jakob
+#   https://github.com/wjakob/layerlab/blob/master/cmake/FindFFTW.cmake, commit 4d58bfdc28891b4f9373dfe46239dda5a0b561c6
+# Modifications:
+#   Copyright (c) 2017, Patrick Bos
 #
-# For the licensing terms see $ROOTSYS/LICENSE.
-# For the list of contributors see $ROOTSYS/README/CREDITS.
-
-# Find the FFTW includes and library.
+# LICENSE:
+#   Copyright (c) 2015, Wenzel Jakob; 2017, Patrick Bos
+#   All rights reserved.
+#   
+#   Redistribution and use in source and binary forms, with or without
+#   modification, are permitted provided that the following conditions are met:
+#   
+#   * Redistributions of source code must retain the above copyright notice, this
+#     list of conditions and the following disclaimer.
+#   
+#   * Redistributions in binary form must reproduce the above copyright notice,
+#     this list of conditions and the following disclaimer in the documentation
+#     and/or other materials provided with the distribution.
+#   
+#   * Neither the name of the copyright holder nor the names of its
+#     contributors may be used to endorse or promote products derived from
+#     this software without specific prior written permission.
+#   
+#   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+#   AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+#   IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+#   DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+#   FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+#   DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+#   SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+#   CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+#   OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+#   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#
+# Usage:
+#   find_package(FFTW [REQUIRED] [QUIET] [COMPONENTS component1 ... componentX] )
+#
+# It sets the following variables:
+#   FFTW_FOUND                  ... true if fftw is found on the system
+#   FFTW_[component]_LIB_FOUND  ... true if the component is found on the system (see components below)
+#   FFTW_LIBRARIES              ... full paths to all found fftw libraries
+#   FFTW_[component]_LIB        ... full path to one of the components (see below)
+#   FFTW_INCLUDE_DIRS           ... fftw include directory paths
+#
+# The following variables will be checked by the function
+#   FFTW_USE_STATIC_LIBS        ... if true, only static libraries are found, otherwise both static and shared.
+#   FFTW_ROOT                   ... if set, the libraries are exclusively searched
+#                                   under this path
+#
+# This package supports the following components:
+#   FLOAT_LIB
+#   DOUBLE_LIB
+#   LONGDOUBLE_LIB
+#   FLOAT_THREADS_LIB
+#   DOUBLE_THREADS_LIB
+#   LONGDOUBLE_THREADS_LIB
+#   FLOAT_OPENMP_LIB
+#   DOUBLE_OPENMP_LIB
+#   LONGDOUBLE_OPENMP_LIB
 #
-# This module defines
-# FFTW_INCLUDE_DIR, where to locate fftw3.h file
-# FFTW_LIBRARIES, the libraries to link against to use fftw3
-# FFTW_FOUND.  If false, you cannot build anything that requires fftw3.
-# FFTW_LIBRARY, where to find the libfftw3 library.
-
-set(FFTW_FOUND 0)
-if(FFTW_LIBRARY AND FFTW_INCLUDE_DIR)
-  set(FFTW_FIND_QUIETLY TRUE)
-endif()
-
-find_path(FFTW_INCLUDE_DIR fftw3.h
-  $ENV{FFTW_DIR}/include
-  $ENV{FFTW3} $ENV{FFTW3}/include $ENV{FFTW3}/api
-  /usr/local/include
-  /usr/include
-  /opt/fftw3/include
-  DOC "Specify the directory containing fftw3.h"
-)
-
-find_library(FFTW_LIBRARY NAMES fftw3 fftw3-3 PATHS
-  $ENV{FFTW_DIR}/lib
-  $ENV{FFTW3} $ENV{FFTW3}/lib $ENV{FFTW3}/.libs
-  /usr/local/lib
-  /usr/lib
-  /opt/fftw3/lib
-  DOC "Specify the fttw3 library here."
-)
-
-if(FFTW_INCLUDE_DIR AND FFTW_LIBRARY)
-  set(FFTW_FOUND 1 )
-  if(NOT FFTW_FIND_QUIETLY)
-     message(STATUS "Found fftw3 includes at ${FFTW_INCLUDE_DIR}")
-     message(STATUS "Found fftw3 library at ${FFTW_LIBRARY}")
-  endif()
-endif()
-
-set(FFTW_LIBRARIES ${FFTW_LIBRARY})
-
-mark_as_advanced(FFTW_FOUND FFTW_LIBRARY FFTW_INCLUDE_DIR)
+
+# TODO (maybe): extend with ExternalProject download + build option
+# TODO: put on conda-forge
+
+
+if( NOT FFTW_ROOT AND DEFINED ENV{FFTWDIR} )
+    set( FFTW_ROOT $ENV{FFTWDIR} )
+endif()
+
+# Check if we can use PkgConfig
+find_package(PkgConfig)
+
+#Determine from PKG
+if( PKG_CONFIG_FOUND AND NOT FFTW_ROOT )
+    pkg_check_modules( PKG_FFTW QUIET "fftw3" )
+endif()
+
+#Check whether to search static or dynamic libs
+set( CMAKE_FIND_LIBRARY_SUFFIXES_SAV ${CMAKE_FIND_LIBRARY_SUFFIXES} )
+
+if( ${FFTW_USE_STATIC_LIBS} )
+    set( CMAKE_FIND_LIBRARY_SUFFIXES ${CMAKE_STATIC_LIBRARY_SUFFIX} )
+else()
+    set( CMAKE_FIND_LIBRARY_SUFFIXES ${CMAKE_FIND_LIBRARY_SUFFIXES_SAV} )
+endif()
+
+if( FFTW_ROOT )
+    # find libs
+
+    find_library(
+        FFTW_DOUBLE_LIB
+        NAMES "fftw3" libfftw3-3
+        PATHS ${FFTW_ROOT}
+        PATH_SUFFIXES "lib" "lib64"
+        NO_DEFAULT_PATH
+        )
+
+    find_library(
+        FFTW_DOUBLE_THREADS_LIB
+        NAMES "fftw3_threads"
+        PATHS ${FFTW_ROOT}
+        PATH_SUFFIXES "lib" "lib64"
+        NO_DEFAULT_PATH
+        )
+
+    find_library(
+        FFTW_DOUBLE_OPENMP_LIB
+        NAMES "fftw3_omp"
+        PATHS ${FFTW_ROOT}
+        PATH_SUFFIXES "lib" "lib64"
+        NO_DEFAULT_PATH
+        )
+
+    find_library(
+        FFTW_DOUBLE_MPI_LIB
+        NAMES "fftw3_mpi"
+        PATHS ${FFTW_ROOT}
+        PATH_SUFFIXES "lib" "lib64"
+        NO_DEFAULT_PATH
+        )
+
+    find_library(
+        FFTW_FLOAT_LIB
+        NAMES "fftw3f" libfftw3f-3
+        PATHS ${FFTW_ROOT}
+        PATH_SUFFIXES "lib" "lib64"
+        NO_DEFAULT_PATH
+        )
+
+    find_library(
+        FFTW_FLOAT_THREADS_LIB
+        NAMES "fftw3f_threads"
+        PATHS ${FFTW_ROOT}
+        PATH_SUFFIXES "lib" "lib64"
+        NO_DEFAULT_PATH
+        )
+
+    find_library(
+        FFTW_FLOAT_OPENMP_LIB
+        NAMES "fftw3f_omp"
+        PATHS ${FFTW_ROOT}
+        PATH_SUFFIXES "lib" "lib64"
+        NO_DEFAULT_PATH
+        )
+
+    find_library(
+        FFTW_FLOAT_MPI_LIB
+        NAMES "fftw3f_mpi"
+        PATHS ${FFTW_ROOT}
+        PATH_SUFFIXES "lib" "lib64"
+        NO_DEFAULT_PATH
+        )
+
+    find_library(
+        FFTW_LONGDOUBLE_LIB
+        NAMES "fftw3l" libfftw3l-3
+        PATHS ${FFTW_ROOT}
+        PATH_SUFFIXES "lib" "lib64"
+        NO_DEFAULT_PATH
+        )
+
+    find_library(
+        FFTW_LONGDOUBLE_THREADS_LIB
+        NAMES "fftw3l_threads"
+        PATHS ${FFTW_ROOT}
+        PATH_SUFFIXES "lib" "lib64"
+        NO_DEFAULT_PATH
+        )
+
+    find_library(
+        FFTW_LONGDOUBLE_OPENMP_LIB
+        NAMES "fftw3l_omp"
+        PATHS ${FFTW_ROOT}
+        PATH_SUFFIXES "lib" "lib64"
+        NO_DEFAULT_PATH
+        )
+
+    find_library(
+        FFTW_LONGDOUBLE_MPI_LIB
+        NAMES "fftw3l_mpi"
+        PATHS ${FFTW_ROOT}
+        PATH_SUFFIXES "lib" "lib64"
+        NO_DEFAULT_PATH
+        )
+
+    #find includes
+    find_path(FFTW_INCLUDE_DIRS
+        NAMES "fftw3.h"
+        PATHS ${FFTW_ROOT}
+        PATH_SUFFIXES "include"
+        NO_DEFAULT_PATH
+        )
+
+else()
+
+    find_library(
+        FFTW_DOUBLE_LIB
+        NAMES "fftw3" libfftw3-3
+        PATHS ${PKG_FFTW_LIBRARY_DIRS} ${LIB_INSTALL_DIR}
+        )
+
+    find_library(
+        FFTW_DOUBLE_THREADS_LIB
+        NAMES "fftw3_threads"
+        PATHS ${PKG_FFTW_LIBRARY_DIRS} ${LIB_INSTALL_DIR}
+        )
+
+    find_library(
+        FFTW_DOUBLE_OPENMP_LIB
+        NAMES "fftw3_omp"
+        PATHS ${PKG_FFTW_LIBRARY_DIRS} ${LIB_INSTALL_DIR}
+        )
+
+    find_library(
+        FFTW_DOUBLE_MPI_LIB
+        NAMES "fftw3_mpi"
+        PATHS ${PKG_FFTW_LIBRARY_DIRS} ${LIB_INSTALL_DIR}
+        )
+
+    find_library(
+        FFTW_FLOAT_LIB
+        NAMES "fftw3f" libfftw3f-3
+        PATHS ${PKG_FFTW_LIBRARY_DIRS} ${LIB_INSTALL_DIR}
+        )
+
+    find_library(
+        FFTW_FLOAT_THREADS_LIB
+        NAMES "fftw3f_threads"
+        PATHS ${PKG_FFTW_LIBRARY_DIRS} ${LIB_INSTALL_DIR}
+        )
+
+    find_library(
+        FFTW_FLOAT_OPENMP_LIB
+        NAMES "fftw3f_omp"
+        PATHS ${PKG_FFTW_LIBRARY_DIRS} ${LIB_INSTALL_DIR}
+        )
+
+    find_library(
+        FFTW_FLOAT_MPI_LIB
+        NAMES "fftw3f_mpi"
+        PATHS ${PKG_FFTW_LIBRARY_DIRS} ${LIB_INSTALL_DIR}
+        )
+
+    find_library(
+        FFTW_LONGDOUBLE_LIB
+        NAMES "fftw3l" libfftw3l-3
+        PATHS ${PKG_FFTW_LIBRARY_DIRS} ${LIB_INSTALL_DIR}
+        )
+
+    find_library(
+        FFTW_LONGDOUBLE_THREADS_LIB
+        NAMES "fftw3l_threads"
+        PATHS ${PKG_FFTW_LIBRARY_DIRS} ${LIB_INSTALL_DIR}
+        )
+
+    find_library(FFTW_LONGDOUBLE_OPENMP_LIB
+        NAMES "fftw3l_omp"
+        PATHS ${PKG_FFTW_LIBRARY_DIRS} ${LIB_INSTALL_DIR}
+        )
+
+    find_library(FFTW_LONGDOUBLE_MPI_LIB
+        NAMES "fftw3l_mpi"
+        PATHS ${PKG_FFTW_LIBRARY_DIRS} ${LIB_INSTALL_DIR}
+        )
+
+    find_path(FFTW_INCLUDE_DIRS
+        NAMES "fftw3.h"
+        PATHS ${PKG_FFTW_INCLUDE_DIRS} ${INCLUDE_INSTALL_DIR}
+        )
+
+endif( FFTW_ROOT )
+
+#--------------------------------------- components
+
+if (FFTW_DOUBLE_LIB)
+    set(FFTW_DOUBLE_LIB_FOUND TRUE)
+    set(FFTW_LIBRARIES ${FFTW_LIBRARIES} ${FFTW_DOUBLE_LIB})
+    add_library(FFTW::Double INTERFACE IMPORTED)
+    set_target_properties(FFTW::Double
+        PROPERTIES INTERFACE_INCLUDE_DIRECTORIES "${FFTW_INCLUDE_DIRS}"
+        INTERFACE_LINK_LIBRARIES "${FFTW_DOUBLE_LIB}"
+        )
+else()
+    set(FFTW_DOUBLE_LIB_FOUND FALSE)
+endif()
+
+if (FFTW_FLOAT_LIB)
+    set(FFTW_FLOAT_LIB_FOUND TRUE)
+    set(FFTW_LIBRARIES ${FFTW_LIBRARIES} ${FFTW_FLOAT_LIB})
+    add_library(FFTW::Float INTERFACE IMPORTED)
+    set_target_properties(FFTW::Float
+        PROPERTIES INTERFACE_INCLUDE_DIRECTORIES "${FFTW_INCLUDE_DIRS}"
+        INTERFACE_LINK_LIBRARIES "${FFTW_FLOAT_LIB}"
+        )
+else()
+    set(FFTW_FLOAT_LIB_FOUND FALSE)
+endif()
+
+if (FFTW_LONGDOUBLE_LIB)
+    set(FFTW_LONGDOUBLE_LIB_FOUND TRUE)
+    set(FFTW_LIBRARIES ${FFTW_LIBRARIES} ${FFTW_LONGDOUBLE_LIB})
+    add_library(FFTW::LongDouble INTERFACE IMPORTED)
+    set_target_properties(FFTW::LongDouble
+        PROPERTIES INTERFACE_INCLUDE_DIRECTORIES "${FFTW_INCLUDE_DIRS}"
+        INTERFACE_LINK_LIBRARIES "${FFTW_LONGDOUBLE_LIB}"
+        )
+else()
+    set(FFTW_LONGDOUBLE_LIB_FOUND FALSE)
+endif()
+
+if (FFTW_DOUBLE_THREADS_LIB)
+    set(FFTW_DOUBLE_THREADS_LIB_FOUND TRUE)
+    set(FFTW_LIBRARIES ${FFTW_LIBRARIES} ${FFTW_DOUBLE_THREADS_LIB})
+    add_library(FFTW::DoubleThreads INTERFACE IMPORTED)
+    set_target_properties(FFTW::DoubleThreads
+        PROPERTIES INTERFACE_INCLUDE_DIRECTORIES "${FFTW_INCLUDE_DIRS}"
+        INTERFACE_LINK_LIBRARIES "${FFTW_DOUBLE_THREADS_LIB}"
+        )
+else()
+    set(FFTW_DOUBLE_THREADS_LIB_FOUND FALSE)
+endif()
+
+if (FFTW_FLOAT_THREADS_LIB)
+    set(FFTW_FLOAT_THREADS_LIB_FOUND TRUE)
+    set(FFTW_LIBRARIES ${FFTW_LIBRARIES} ${FFTW_FLOAT_THREADS_LIB})
+    add_library(FFTW::FloatThreads INTERFACE IMPORTED)
+    set_target_properties(FFTW::FloatThreads
+        PROPERTIES INTERFACE_INCLUDE_DIRECTORIES "${FFTW_INCLUDE_DIRS}"
+        INTERFACE_LINK_LIBRARIES "${FFTW_FLOAT_THREADS_LIB}"
+        )
+else()
+    set(FFTW_FLOAT_THREADS_LIB_FOUND FALSE)
+endif()
+
+if (FFTW_LONGDOUBLE_THREADS_LIB)
+    set(FFTW_LONGDOUBLE_THREADS_LIB_FOUND TRUE)
+    set(FFTW_LIBRARIES ${FFTW_LIBRARIES} ${FFTW_LONGDOUBLE_THREADS_LIB})
+    add_library(FFTW::LongDoubleThreads INTERFACE IMPORTED)
+    set_target_properties(FFTW::LongDoubleThreads
+        PROPERTIES INTERFACE_INCLUDE_DIRECTORIES "${FFTW_INCLUDE_DIRS}"
+        INTERFACE_LINK_LIBRARIES "${FFTW_LONGDOUBLE_THREADS_LIB}"
+        )
+else()
+    set(FFTW_LONGDOUBLE_THREADS_LIB_FOUND FALSE)
+endif()
+
+if (FFTW_DOUBLE_OPENMP_LIB)
+    set(FFTW_DOUBLE_OPENMP_LIB_FOUND TRUE)
+    set(FFTW_LIBRARIES ${FFTW_LIBRARIES} ${FFTW_DOUBLE_OPENMP_LIB})
+    add_library(FFTW::DoubleOpenMP INTERFACE IMPORTED)
+    set_target_properties(FFTW::DoubleOpenMP
+        PROPERTIES INTERFACE_INCLUDE_DIRECTORIES "${FFTW_INCLUDE_DIRS}"
+        INTERFACE_LINK_LIBRARIES "${FFTW_DOUBLE_OPENMP_LIB}"
+        )
+else()
+    set(FFTW_DOUBLE_OPENMP_LIB_FOUND FALSE)
+endif()
+
+if (FFTW_FLOAT_OPENMP_LIB)
+    set(FFTW_FLOAT_OPENMP_LIB_FOUND TRUE)
+    set(FFTW_LIBRARIES ${FFTW_LIBRARIES} ${FFTW_FLOAT_OPENMP_LIB})
+    add_library(FFTW::FloatOpenMP INTERFACE IMPORTED)
+    set_target_properties(FFTW::FloatOpenMP
+        PROPERTIES INTERFACE_INCLUDE_DIRECTORIES "${FFTW_INCLUDE_DIRS}"
+        INTERFACE_LINK_LIBRARIES "${FFTW_FLOAT_OPENMP_LIB}"
+        )
+else()
+    set(FFTW_FLOAT_OPENMP_LIB_FOUND FALSE)
+endif()
+
+if (FFTW_LONGDOUBLE_OPENMP_LIB)
+    set(FFTW_LONGDOUBLE_OPENMP_LIB_FOUND TRUE)
+    set(FFTW_LIBRARIES ${FFTW_LIBRARIES} ${FFTW_LONGDOUBLE_OPENMP_LIB})
+    add_library(FFTW::LongDoubleOpenMP INTERFACE IMPORTED)
+    set_target_properties(FFTW::LongDoubleOpenMP
+        PROPERTIES INTERFACE_INCLUDE_DIRECTORIES "${FFTW_INCLUDE_DIRS}"
+        INTERFACE_LINK_LIBRARIES "${FFTW_LONGDOUBLE_OPENMP_LIB}"
+        )
+else()
+    set(FFTW_LONGDOUBLE_OPENMP_LIB_FOUND FALSE)
+endif()
+
+if (FFTW_DOUBLE_MPI_LIB)
+    set(FFTW_DOUBLE_MPI_LIB_FOUND TRUE)
+    set(FFTW_LIBRARIES ${FFTW_LIBRARIES} ${FFTW_DOUBLE_MPI_LIB})
+    add_library(FFTW::DoubleMPI INTERFACE IMPORTED)
+    set_target_properties(FFTW::DoubleMPI
+        PROPERTIES INTERFACE_INCLUDE_DIRECTORIES "${FFTW_INCLUDE_DIRS}"
+        INTERFACE_LINK_LIBRARIES "${FFTW_DOUBLE_MPI_LIB}"
+        )
+else()
+    set(FFTW_DOUBLE_MPI_LIB_FOUND FALSE)
+endif()
+
+if (FFTW_FLOAT_MPI_LIB)
+    set(FFTW_FLOAT_MPI_LIB_FOUND TRUE)
+    set(FFTW_LIBRARIES ${FFTW_LIBRARIES} ${FFTW_FLOAT_MPI_LIB})
+    add_library(FFTW::FloatMPI INTERFACE IMPORTED)
+    set_target_properties(FFTW::FloatMPI
+        PROPERTIES INTERFACE_INCLUDE_DIRECTORIES "${FFTW_INCLUDE_DIRS}"
+        INTERFACE_LINK_LIBRARIES "${FFTW_FLOAT_MPI_LIB}"
+        )
+else()
+    set(FFTW_FLOAT_MPI_LIB_FOUND FALSE)
+endif()
+
+if (FFTW_LONGDOUBLE_MPI_LIB)
+    set(FFTW_LONGDOUBLE_MPI_LIB_FOUND TRUE)
+    set(FFTW_LIBRARIES ${FFTW_LIBRARIES} ${FFTW_LONGDOUBLE_MPI_LIB})
+    add_library(FFTW::LongDoubleMPI INTERFACE IMPORTED)
+    set_target_properties(FFTW::LongDoubleMPI
+        PROPERTIES INTERFACE_INCLUDE_DIRECTORIES "${FFTW_INCLUDE_DIRS}"
+        INTERFACE_LINK_LIBRARIES "${FFTW_LONGDOUBLE_MPI_LIB}"
+        )
+else()
+    set(FFTW_LONGDOUBLE_MPI_LIB_FOUND FALSE)
+endif()
+
+#--------------------------------------- end components
+
+set( CMAKE_FIND_LIBRARY_SUFFIXES ${CMAKE_FIND_LIBRARY_SUFFIXES_SAV} )
+
+include(FindPackageHandleStandardArgs)
+
+find_package_handle_standard_args(FFTW
+    REQUIRED_VARS FFTW_INCLUDE_DIRS
+    HANDLE_COMPONENTS
+    )
+
+mark_as_advanced(
+    FFTW_INCLUDE_DIRS
+    FFTW_LIBRARIES
+    FFTW_FLOAT_LIB
+    FFTW_DOUBLE_LIB
+    FFTW_LONGDOUBLE_LIB
+    FFTW_FLOAT_THREADS_LIB
+    FFTW_DOUBLE_THREADS_LIB
+    FFTW_LONGDOUBLE_THREADS_LIB
+    FFTW_FLOAT_OPENMP_LIB
+    FFTW_DOUBLE_OPENMP_LIB
+    FFTW_LONGDOUBLE_OPENMP_LIB
+    FFTW_FLOAT_MPI_LIB
+    FFTW_DOUBLE_MPI_LIB
+    FFTW_LONGDOUBLE_MPI_LIB
+    )
diff --git a/cmake/modules/SearchInstalledSoftware.cmake b/cmake/modules/SearchInstalledSoftware.cmake
index fb3ba29c6804a..9a697a230e52d 100644
--- a/cmake/modules/SearchInstalledSoftware.cmake
+++ b/cmake/modules/SearchInstalledSoftware.cmake
@@ -583,23 +583,8 @@ if(fftw3)
   endif()
 endif()
 if(builtin_fftw3)
-  set(FFTW_VERSION 3.3.10)
-  message(STATUS "Downloading and building FFTW version ${FFTW_VERSION}")
-  set(FFTW_LIBRARIES ${CMAKE_BINARY_DIR}/lib/libfftw3.a)
-  ExternalProject_Add(
-    FFTW3
-    URL ${lcgpackages}/fftw-${FFTW_VERSION}.tar.gz
-    URL_HASH SHA256=56c932549852cddcfafdab3820b0200c7742675be92179e59e6215b340e26467
-    INSTALL_DIR ${CMAKE_BINARY_DIR}
-    CONFIGURE_COMMAND ./configure --prefix=<INSTALL_DIR>
-    BUILD_COMMAND make CFLAGS=-fPIC
-    LOG_DOWNLOAD 1 LOG_CONFIGURE 1 LOG_BUILD 1 LOG_INSTALL 1 LOG_OUTPUT_ON_FAILURE 1
-    BUILD_IN_SOURCE 1
-    BUILD_BYPRODUCTS ${FFTW_LIBRARIES}
-    TIMEOUT 600
-  )
-  set(FFTW_INCLUDE_DIR ${CMAKE_BINARY_DIR}/include)
-  set(FFTW3_TARGET FFTW3)
+  list(APPEND ROOT_BUILTINS BUILTIN_FFTW3)
+  add_subdirectory(builtins/fftw3)
   set(fftw3 ON CACHE BOOL "Enabled because builtin_fftw3 requested (${fftw3_description})" FORCE)
 endif()
 
diff --git a/math/fftw/CMakeLists.txt b/math/fftw/CMakeLists.txt
index 0c8d8e936e0c3..2bdb5629f4fad 100644
--- a/math/fftw/CMakeLists.txt
+++ b/math/fftw/CMakeLists.txt
@@ -20,12 +20,9 @@ ROOT_STANDARD_LIBRARY_PACKAGE(FFTW
     src/TFFTComplexReal.cxx
     src/TFFTReal.cxx
     src/TFFTRealComplex.cxx
+  LIBRARIES
+    FFTW::Double
   DEPENDENCIES
     Core
     MathCore
-  BUILTINS
-    FFTW3
 )
-
-target_include_directories(FFTW PRIVATE ${FFTW_INCLUDE_DIR})
-target_link_libraries(FFTW PRIVATE ${FFTW_LIBRARIES})
diff --git a/roofit/roofitcore/CMakeLists.txt b/roofit/roofitcore/CMakeLists.txt
index 6bf5ab9289408..b3cd7991c736d 100644
--- a/roofit/roofitcore/CMakeLists.txt
+++ b/roofit/roofitcore/CMakeLists.txt
@@ -489,6 +489,7 @@ endif()
 
 if(fftw3)
   target_compile_definitions(RooFitCore PUBLIC ROOFIT_MATH_FFTW3)
+  target_link_libraries(RooFitCore PRIVATE FFTW::Double)
 endif()
 
 target_include_directories(RooFitCore PUBLIC $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/res>)