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

In a small bowl, combine the all-purpose flour, cornstarch, and baking powder.

In a large mixing bowl, cream together the softened salted butter and granulated sugar until light and fluffy, about 2-3 minutes. Mix in lemon zest and lavender buds.

Incorporate the large egg into the butter mixture until fully combined.

Gradually add the dry ingredients to the wet mixture, mixing on low speed until just combined.

Using a cookie scoop, drop tablespoon-sized dough balls onto the prepared baking sheets, spacing them about 2 inches apart. Flatten each to about 1/3 inch thick.

Bake for 12-15 minutes, checking at 10 minutes for edges to be golden and centers soft.

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

For the glaze, whisk together powdered sugar, fresh lemon juice, and lavender extract in a medium bowl. Tint with food coloring if desired.

Spoon glaze over cooled cookies, allowing it to drizzle down the sides. Garnish with additional lavender buds and lemon zest if desired. Let glaze set for 30 minutes before serving.