The night before (or earlier)

Cup of Yum
1. Combine sugar and lavender in an airtight container.

To make the cupcakes

1. In a small bowl, combine 2T milk, egg whites, and vanilla extract; whisk briefly to blend.
2. In a second larger bowl, combine the flour, sugar/lavender mixture, cornstarch, lemon zest, baking powder, and salt. Mix briefly on low speed to combine, about 30 seconds.
3. Add in the butter and mix on low speed until the mixture resembles wet sand, about 30 seconds.
4. Mix in the remaining 3/8 cup milk, then increase the speed to medium and beat for about 2 minutes more.
5. With the mixture on low speed, add the egg white mixture in three additions, mixing for about 20 seconds after each addition. Scrape down the bowl as needed.
6. Fill lined 12 count cupcake pan about two-thirds of the way full.
7. Bake at 350F, rotating the pans halfway through, until a toothpick inserted in the center comes out clean, about 18 minutes. Let cool in the pan briefly, then transfer to a wire rack and allow to cool completely before frosting.