Preheat oven to 350°F (175°C). Lightly grease a mini muffin tin or use nonstick spray.

Cream butter and sugars: In a large bowl, beat together the softened butter, powdered sugar, and granulated sugar until light and fluffy.

Add vanilla: Mix in the vanilla extract.

Add dry ingredients: Gradually stir in flour and salt until the dough comes together. The dough will be soft but not sticky.

Form the cups: Scoop about 1 tablespoon of dough into each mini muffin cup. Press the dough into the bottom and up the sides to form a cup shape.

Bake: Bake for 12–15 minutes, or until the edges are lightly golden.

Shape while warm: Immediately after baking, use the back of a spoon or a small tart tamper to gently press down the center of each cup to reinforce the well.

Cool: Let cool in the pan for 10 minutes, then remove to a wire rack to cool completely.

Fill and serve: Once cooled, fill with your favorite fillings — chocolate ganache, lemon curd, jam, Nutella, cheesecake filling, whipped cream, or fruit.