Cream the butter and powdered sugar in a large bowl until light and fluffy.

Add the vanilla, lemon juice, and zest, mixing until well combined.

In another bowl, whisk together the flour, cornstarch, and salt.

Gradually add the dry mixture to the wet ingredients, forming a smooth dough.

Wrap the dough in plastic wrap and chill for 30 minutes.

Preheat your oven to 350°F and line baking sheets with parchment paper.

Scoop out tablespoon-sized portions of dough and roll them into balls.

Place the balls about 2 inches apart on the tray and gently flatten each one.

Bake for 10–12 minutes, keeping an eye on them until the edges are set but still pale.

Let the cookies cool on the tray for 5 minutes before transferring to a wire rack.

For the glaze, whisk together powdered sugar, lemon juice, and zest until smooth.

Dip the tops of the cooled cookies into the glaze or drizzle it over them.

Let the cookies sit until the glaze hardens.