In a food processor, add the flour, powdered sugar, and salt, and mix until combined.
Add the cold cubed butter, and blend until there are pea-sized pieces of butter. If you don't have a food processor, you can do it by hand, mixing the cold butter into the flour mixture. Make sure that your hands are cold.
Then, add the egg, and the vanilla extract and mix until a dough forms. Try not to overmix the dough.
Cover the dough with plastic wrap and let it chill in the fridge for at least an hour.
Transfer the dough onto a clean floured surface and roll it with a rolling pin into a rectangle.
Use a cookie cutter or a round bowl (1 inch larger than the mini tart pans) and cut small rounds of the pastry.
Place the pastry inside the mini tart pans and press it down using your clean hands.
Cut off the extra edges. Make holes in the bottom of the pan with a fork and place them in the freezer for at least 20 minutes.
Bake in a 180c (350f) preheated oven for about 15-20 minutes or until the crust is a light golden brown color. Remove from the oven and let it cool while making the filling.
Notes
Use COLD butterfor the crust, we suggest cutting the butter into cubes and then placing it in the fridge, so when you are ready to use it, it will be very cold.
If the crust puffs a bit while baking, press it down using a cup.
Before you bake the shells, place them in the freezer for 20 minutes to firm up. This ensures that the pastry keeps its shape and bakes perfectly.
Let the pastry dough rest in the fridge for at least 1 hour before handling it. This makes sure that the pastry doesn't rise quicklywhile baking.
Use an easy-release tartlets pan. We use an easy-release tartlets pan for all of our tart recipes. This makes sure that your delicious mini fruit tart will be easy to release from the pan.
If the dough is too hard to roll, let it sit at room temperature until it's easier to roll out.