01 - Preheat oven to 350°F. Grease a 12-cup muffin tin thoroughly or line with cupcake liners for easy removal.
02 - In a medium bowl, whisk together flour, baking powder, baking soda, salt, and chopped lavender until well combined.
03 - In a large bowl, beat softened butter and granulated sugar with an electric mixer until light and fluffy, approximately 2-3 minutes.
04 - Beat in eggs one at a time, ensuring each is fully incorporated before adding the next. Mix in vanilla extract until smooth.
05 - Combine whole milk and sour cream in a small bowl, stirring until uniform and smooth.
06 - Add flour mixture to the butter mixture in three additions, alternating with the milk and sour cream mixture. Begin and end with flour, mixing until just combined. Do not overmix.
07 - Toss blueberries with 1 tablespoon flour in a small bowl to prevent sinking. Gently fold coated blueberries into the batter.
08 - Divide batter evenly among prepared muffin cups, filling each about two-thirds full to allow for rising.
09 - Bake for 22-25 minutes until tops are golden brown and a toothpick inserted in the center comes out clean.
10 - Let cakes cool in the pan for 5 minutes before transferring to a wire rack. Allow to cool completely before glazing.
11 - Whisk powdered sugar and lemon juice in a small bowl until smooth and drizzleable. Drizzle over completely cooled cakes.