Preheat your oven to 350°F (180°C). Line 2 baking sheets with parchment paper.

In a small bowl, whisk together the flour, cornstarch, and baking powder. Set aside.

Using a large mixing bowl and a stand mixer or electric mixer, cream the butter, sugar, lemon zest, and lavender until light and fluffy (about 2-3 minutes). Scrape down the sides of the bowl.

Mix in the egg until well combined.

Add the flour mixture on low speed and mix until just combined. The dough may seem slightly dry.

Use a small cookie scoop to drop 1-tablespoon-sized balls of dough onto the prepared baking sheets, spacing them 2 inches apart.

Gently flatten each ball with your palms until 1/3 inch thick.

Bake for 12-15 minutes until the center is set and edges are slightly golden. Bake one sheet at a time.

Cool the cookies on the baking sheet for 5 minutes, then transfer to a wire rack to cool completely.

In a medium bowl, whisk together powdered sugar, lemon juice, and lavender extract to make the glaze. Add food coloring if desired.

Spoon glaze over each cookie. Sprinkle with lavender buds and lemon zest if desired. Let the icing set for 30 minutes before enjoying.

Store cookies in an airtight container at room temperature for up to 4 days, separating layers with wax paper.