Preheat your oven to 350°F (175°C) and line a cupcake tin with liners.
In a mixing bowl, cream together the butter and sugar until light and fluffy.
Add the eggs one at a time, beating well after each addition.
Mix in the lemon zest and vanilla extract.
In another bowl, whisk together the flour, baking powder, ground lavender, and salt.
Gradually add the dry ingredients to the wet ingredients, alternating with the milk. Begin and end with the dry ingredients.
Divide the batter evenly among the cupcake liners, filling each about ⅔ full.
Bake for 18-20 minutes, or until a toothpick inserted into the center comes out clean.
Allow the cupcakes to cool in the tin for 5 minutes, then transfer to a wire rack to cool completely.