Combine the flour, confectioner's sugar, cocoa powder and salt in the bowl of a food processor. Pulse a couple times to thoroughly combine.
1 ¼ cup all purpose flour, ½ cup confectioners sugar, ¼ cup cocoa powder, ½ teaspoon fine sea salt
Scatter the butter over the flour mixture. Pulse until the mixture resembles coarse crumbs.
½ cup unsalted butter, cold and cubed
Whisk together the egg yolk and cream in a small bowl. Add the egg yolk mixture while pulsing. Pulse the mixture until it forms large clumps.
1 large egg yolk, cold, 1 tablespoon heavy cream
Turn the dough onto a lightly floured surface and form into a ball. It should come together easily without being sticky. Flatten ball slightly with your hands to form a thick disc. Wrap with plastic wrap and refrigerate for at least 1 hour.
Place your chilled dough on a lightly floured surface. Let the dough sit for a 5-10 minutes, if necessary, until pliable. Roll out the dough into a 12" circle.
Loosely roll up the dough over a rolling pin. Unroll the dough over a 9.5" tart pan.
Ease the dough into the pan. Avoid stretching the dough. Use the tips of your fingers to ensure the dough is flush with the bottom and sides of the pan. Cut off the excess. Prick the dough with a fork a couple times.
Refrigerate the crust for one hour, or freeze for 30 minutes. Meanwhile, place a baking sheet in the oven and preheat to 400℉.
Lightly spray a piece of aluminum foil or parchment paper with cooking spray. Press the foil into the tart shell, covering the edges. Fill the shell with pie weights.
Place the tart shell into the oven on top of the baking sheet and bake for 22 minutes. Remove the shell from the oven and remove the foil and pie weights.
Place the tart shell back into the oven and bake for an additional 5 minutes. Let the tart shell cool completely.
Spread the raspberry jam evenly over the cooled tart shell.
½ cup raspberry jam