Step 1: Make the Tartlet Shells
Prepare the Dough: In a large mixing bowl, combine 1 1/4 cups all-purpose flour and 1/4 cup powdered sugar. Add the cold, cubed unsalted butter and use a pastry cutter or your fingers to blend until the mixture resembles coarse crumbs.
Add Egg Yolk: Mix in the egg yolk and gradually add 1-2 tablespoons of cold water, stirring until the dough starts to come together. Avoid overworking the dough.
Chill the Dough: Form the dough into a disk, wrap it in plastic wrap, and refrigerate for at least 30 minutes to firm up.
Step 2: Preheat the Oven
Heat Things Up: Preheat your oven to 350°F (175°C) while the dough chills.
Step 3: Roll and Shape the Tartlet Shells
Roll Out the Dough: On a lightly floured surface, roll out the chilled dough to about 1/8 inch thick. Cut out circles that are slightly larger than your tartlet pans (about 4 to 5 inches in diameter).
Form the Tartlets: Gently press the dough circles into the tartlet pans, trimming any excess dough hanging over the edges. Prick the bottoms with a fork to prevent bubbling.
Step 4: Bake the Tartlet Shells
