Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.

In a large mixing bowl, cream the softened unsalted butter and powdered sugar until light and fluffy (about 2-3 minutes).

Gradually add cornstarch, all-purpose flour, lemon zest, fresh lemon juice, vanilla extract, and a pinch of salt to the creamed mixture. Mix until a soft dough forms.

Roll the dough into 1-inch balls and flatten them slightly on the baking sheet.

Bake for 10-12 minutes, until lightly golden around the edges but soft in the center.

Allow to cool for about 5 minutes on the baking sheet before transferring to a wire rack. Dust with powdered sugar.