Step 1 In the bowl of a food processor, pulse the flour, sugar and salt together to combine. Add the frozen butter cubes and pulse until the butter is reduced to pea-sized balls. Add the creme fraiche and pulse until mixed and the dough begins to form clumps.
Step 2 Remove the dough and form into a coarse ball, then flatten to form a disk. Cover with plastic wrap and chill for at least 2 hours, preferably overnight.
Step 3Roll the dough larger than the diameter of the 10-inch tart pan, approximately 12 inches in diameter. Chill the rolled dough for 30 minutes, then carefully fit it into the pan, trimming and saving any leftover dough. Freeze the dough until ready to bake, at least 1 hour.
Step 4Heat the oven to 375 degrees. Line the inside of the tart shell with foil and beans or pie weights. Blind-bake the frozen shell until set and golden on the sides, 20 to 25 minutes; the dough will shrink a bit on the sides. Remove the weights and foil and continue to bake until the crust is fully set and a deep golden brown, an additional 10 to 20 minutes.
Step 5Cool on a rack, then chill the shell until ready to complete the tart (chill up to one day before baking).