In a large bowl, combine the flour, powdered sugar, almond flour, and salt.
Quickly cut in the cold butter using a dough blender, two forks, or your fingers until blended and no pieces are larger than a pea and the dough has a crumbly texture.
Mix in the eggs to bring the dough together until smooth.
Form the dough into a disc, wrap in plastic, and refrigerate until chilled, about 1 hour or up to two days.
Grease 24 tartlet cavities with butter.
On a lightly floured surface or between two sheets of wax paper, roll the refrigerated dough into an even, thin circle about 1/8 inch (3 millimeters) thick.
Cut out circles of dough using a cutter slightly larger than the width of the tartlet pans.
Press each circle into the prepared pan. Bring together the scraps of dough and roll out again, then cut if needed to make more circles.
Place the prepared tartlet pans in the refrigerator for 30 minutes.
Preheat oven to 325˚F (160˚C).
Cover each circle of dough in the pan with parchment and add pie weights or uncooked rice. Bake in the preheated oven until set and lightly golden, 12-15 minutes.
Remove from the oven and set aside for a few minutes before carefully removing the pie weights. Cool to room temperature before filling.