01 - Preheat oven to 350°F. Grease a 12-cup muffin tin generously 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 thoroughly 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, whisking briefly to blend.
06 - Add flour mixture to butter mixture in three portions, alternating with the milk-sour cream mixture. Begin and end with flour. Mix until just combined, being careful not to overmix.
07 - Toss blueberries with 1 tablespoon flour in a small bowl to prevent sinking. Gently fold into batter until evenly distributed.
08 - Divide batter evenly among prepared muffin cups, filling each about 2/3 full to allow for rising during baking.
09 - Bake for 22-25 minutes until a toothpick inserted into the center comes out clean or with just a few moist crumbs.
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 until smooth and drizzle-consistency. Drizzle over completely cooled cakes just before serving.