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 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.
05 - Combine milk and sour cream in a small bowl, stirring until smooth.
06 - Add flour mixture to butter mixture in three additions, alternating with the milk and sour cream mixture. Begin and end with flour. Mix until just combined, being careful not to overmix.
07 - Toss blueberries with 1 tablespoon flour to coat, then gently fold into the batter until evenly distributed.
08 - Divide batter evenly among prepared muffin cups, filling each about 2/3 full.
09 - Bake for 22-25 minutes, or until a toothpick inserted in the center comes out clean.
10 - Let cakes cool in the pan for 5 minutes, then transfer to a wire rack to cool completely.
11 - Whisk powdered sugar and lemon juice until smooth. Drizzle over cooled cakes just before serving.