Add Flour, Powdered Sugar, Salt, and Almond Flour to the bowl of a food processor. Pulse a couple times to combine ingredients.
Add Butter pieces. Pulse until the Butter is coarsely cut in, some pieces will be the size of oatmeal, others the size of peas.
Add beaten Egg, a little at a time, pulsing after each addition.
Once all of the egg is added, process the dough in long pulses, about 10 seconds each, until it comes together into large clumps.
Turn out onto a large piece of plastic wrap. Cover with another large piece of plastic wrap. Press the dough into a 7"-8" circle that is about 1/2" thick. Wrap edges of plastic wrap under the dough circle, so the dough is completely covered, top and bottom.
Pop your dough in the freezer for 15-20 minutes until very cold, but not frozen.
After 15 minutes in freezer, remove the dough and unwrap. Place on a piece of parchment paper and roll out into a 12" round, about 1/8" thick. It will be nice and stiff, and very workable.
Transfer dough to your tart pan. Press into the corners and up the sides. Trim the edges so there is a little extra sticking over the top of the pan. Gently crimp the top with your thumb and pointer finger to make a "fluted" edge.
Pop the formed crust back into the freezer for at least 30 minutes, preferably longer.
Preheat oven to 375℉.
Remove tart crust from freezer. Puncture the bottom of the crust all over with a knife, creating vent holes for the steam as it is baking.
Bake for 10-15 minutes. Remove from oven and press the bottom down with a piece of foil as it will more than likely have bubbled up a bit. Return to the oven for 5-10 minutes, until golden brown.
Remove Crust from oven. Set aside.