01 - Preheat oven to 350°F. Grease a 12-cup muffin tin or line with cupcake liners.
02 - In a medium bowl, whisk together flour, baking powder, baking soda, salt, and chopped lavender until well blended.
03 - In a large bowl, beat softened butter and granulated sugar until light and fluffy, about 2-3 minutes.
04 - Beat in eggs one at a time, mixing thoroughly after each addition. Stir in vanilla extract.
05 - Combine milk and sour cream in a small bowl, whisking until smooth.
06 - Add flour mixture to butter mixture in three additions, alternating with milk mixture, beginning and ending with flour. Mix until just combined.
07 - Toss blueberries with 1 tablespoon flour in a small bowl to prevent sinking.
08 - Gently fold floured blueberries into the batter until evenly distributed.
09 - Divide batter evenly among prepared muffin cups, filling each about 2/3 full.
10 - Bake for 22-25 minutes, or until a toothpick inserted in the center comes out clean.
11 - Cool in pan for 5 minutes, then transfer to wire rack to cool completely before glazing.
12 - Whisk powdered sugar and lemon juice until smooth. Drizzle over cooled cakes just before serving.