Preheat your oven to 350°F (180°C) and line a baking sheet with parchment paper.

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

Add the lemon zest, lemon juice, vanilla extract, and lavender to the butter mixture. Mix until combined.

In a separate bowl, whisk together the all-purpose flour and cornstarch. Gradually add this mixture to the wet ingredients, blending until a smooth dough forms.

Scoop about a tablespoon of dough and roll it into a ball. Place each ball on the prepared baking sheet and gently flatten them with your palm.

Bake in the preheated oven for 12-15 minutes, or until the edges are just starting to turn golden. Let them cool on the baking sheet for a few minutes before transferring them to a wire rack to cool completely.

If you'd like to glaze your cookies, mix powdered sugar with a few teaspoons of lemon juice until you reach a drizzle-able consistency. Drizzle over cooled cookies.