1. Preheat oven to 350°F. Line a cupcake pan with 12 cupcake liners.

2. Place the lavender and milk in a blender and blend or pulse for a few seconds to blend the lavender into small bits.

3. Whisk the cake flour, baking powder, baking soda, and salt in a medium bowl.

4. In the bowl of a stand mixer or large bowl with electric mixer, beat butter and sugar on high speed to cream for 2 minutes until light and fluffy. Scrape down the bowl.

5. Add egg whites, vanilla extract, lavender extract, and vanilla bean seeds and beat on medium-high speed until smooth and combined, about 2 minutes.

6. Beat in Greek yogurt or sour cream. Scrape down the sides and bottom of the bowl.

7. With mixer on low speed, gradually add dry ingredients until just incorporated.

8. Pour in lavender milk with mixer on low and mix until just combined. Do not overmix.

9. Fill each cupcake liner 2/3 full with batter.

10. Bake for 18–22 minutes, or until a toothpick inserted in the center comes out clean. Let cool completely before frosting.

11. To make the frosting, beat room temperature butter in a large bowl until smooth, about 3 minutes.

12. Sift in powdered sugar and add heavy cream, honey, lemon zest, salt, and optional food coloring. Beat until smooth and fluffy, about 3 more minutes.

13. Pipe frosting onto cooled cupcakes using a piping bag or plastic bag with the tip cut off.

14. Garnish with additional lavender or edible flowers, if desired.