Step 1 Cream the butter and sugar together in the bowl of a standing mixer fitted with a paddle attachment until it has a creamy consistency. Alternatively, cream the butter and sugar together in a large bowl using a hand mixer. With the mixer on, add the egg yolk until it is incorporated, then add the egg and incorporate completely.
Step 2 In a separate bowl, sift together the almond flour, flour and baking powder. Add the dry ingredients to the mixing bowl slowly and continue mixing until the dough is thoroughly combined. The dough should be slightly sticky but not wet. If the dough is too dry and crumbly, add up to 1 tablespoon of water to moisten the dough.
Step 3Divide the dough into two equal portions. Shape each portion into a circle and cover tightly with plastic wrap. Refrigerate one of the portions, and allow it to rest for at least 1 hour. The remaining portion can be frozen for up to 6 months. (For frozen dough, thaw in the refrigerator before using.)
Step 4Heat the oven to 350 degrees. Remove the chilled dough from the refrigerator, and place on a lightly floured work surface. Roll out the dough into a circle slightly less than one-fourth-inch thick and about 12 inches in diameter. Gently drape the dough into a 9-inch pie pan, and trim off any excess dough so that the crust is flush with the sides of the pan. With a fork, prick holes all over the dough to allow steam to escape during baking. Bake until golden brown, 15 to 25 minutes. Allow to cool on a rack.