Making mini tart shells from-scratch is so much easier than you think. And, you don't even need a tart mold - just a cupcake pan or muffin tin! The crust is uber buttery, flaky, and simple to make with just 6 basic ingredients. Fill them with custard, ganache, lemon curd, or any of your favorite fillings. They're the best!
Add the flour, powdered sugar, and Kosher salt to the bowl of a food processor. Pulse a few times to combine.
Then, toss the butter cubes in the flour mixture. Pulse until the mixture is sandy. You should have butter chunks that are pea-sized and smaller.
Add the egg and vanilla extract. Turn on the food processor and blitz just until the dough comes together in big clumps. It should be the texture of Play-Doh.
Turn the dough onto a lightly-floured surface and knead it a few times with your hands until it's nice and smooth. Divide the dough half and pat each portion into a 1/2-inch thick disc. Wrap in plastic wrap or parchment paper and refrigerate for at least 1 hour.
Lightly dust a surface with flour. Working one round of dough at a time, roll the dough until it's about 1/8-inch thick. Use a 3-3 1/2-inch round biscuit cutter to cut out as many dough circles as you can. Gather & re-roll the scraps of dough and cut out as many circles as you can. Repeat with the other disc of dough. You should have about 32 dough circles in total.
With an offset spatula or butter knife, transfer the dough circles to the cups of the cupcake pan. Evenly press the dough circles into the cups, using a pastry tamper or spoon to gently press the dough into the edges & bottoms of the cups. Then, use the tines of a fork to dock the bottoms of the crusts. Refrigerate for 1 hour, until the crusts are very cold. (This will help prevent shrinking.)
Preheat the oven to 350°F (177°C). Place a paper cupcake liner in the center of each crust. Fill the cupcake liners with pie weights, dried beans, or dried rice.
Par-bake (for baked fillings) - Bake the crusts for 15-18 minutes, until they are set and golden-brown on the edges. Carefully remove the paper liners from the crusts. (They should not stick. If they are sticking, bake the crusts for another 2-3 minutes, until the paper liners easily release.) Fill and bake according to the recipe directions.
Blind-bake (for no-bake fillings) - Bake the crusts for 15-18 minutes, until the crusts are set and golden-brown on the edges. Carefully remove the paper liners from the crusts. (They should not stick. If they are sticking, bake the crusts for another 2-3 minutes, until the paper liners easily release.) Bake uncovered for another 7-10 minutes, until the crusts are crisp and deep golden-brown. They will shrink a tad, but should still be deep enough to fill. Let the crusts cool for 10-15 minutes and then transfer them to a wire rack to cool completely before filling.
Notes
For the best results, weigh the ingredients with a kitchen scale. If you don't have a scale, here's how to measure the flour. First, fluff it with a whisk. Spoon the fluffed flour into the measuring cup and level it off without packing the flour into the cup.It's important to use very cold ingredients. Cold butter is key for those flaky layers!You can also use a muffin pan, but you will end up with larger shells. Just use a 4-4 1/2-inch round biscuit cutter instead.You'll only want to gather and re-roll the dough once (or twice at the very most). After two rolls, the dough will start to pull in on itself which will cause the shells to shrink.Make the dough by hand - Mix the flour, powdered sugar, & salt in a large mixing bowl. Add the butter cubes and use a pastry cutter or two butter knives to cut the butter into the dry ingredients until the mixture is sandy. (You should have some larger, pea-sized chunks of butter.) Add the egg and vanilla and mix by hand with a rubber spatula until you have a smooth dough that's the texture of Play-Doh.