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

In a large mixing bowl, combine softened unsalted butter and powdered sugar. Cream together on medium speed for 2-3 minutes until light and fluffy.

Mix in the lemon zest, lemon juice, and vanilla extract until well combined.

In a separate bowl, whisk together flour, cornstarch, and salt. Gradually add this mixture to the wet ingredients, stirring gently until a soft dough forms.

Scoop the dough using a tablespoon, roll into balls, and place on the prepared baking sheet. Lightly press each cookie to flatten.

Bake for 10-12 minutes until edges are set but centers remain soft. Remove from oven.

Allow cookies to cool on the baking sheet for about 5 minutes before transferring to a wire rack to cool completely.

In a small bowl, whisk together powdered sugar and lemon juice until smooth to prepare the glaze.

Once cookies are cool, drizzle or dip them into the lemon glaze and allow to set for about 15 minutes.