Preheat oven to 425F. Line a 12-cup muffin tin with muffin liners and set aside.
In a large bowl, beat butter and sugar until smooth and creamy. Beat in lemon zest, juice, eggs, yogurt, buttermilk, and vanilla until smooth.
In a separate medium bowl, combine 2 cups flour, lavender, baking powder, baking soda, and salt. Fold into liquid mixture until batter is just combined. In a small bowl, toss blueberries with remaining 1 tablespoon flour and fold into batter.
Fill muffin cups to brim with muffin batter and smooth tops. Bake muffins at 425F 5 minutes, then reduce heat to 375F and continue baking an additional 15-20 minutes until a toothpick inserted in center of muffin comes out clean.
Cool muffins 20 minutes in pan, then transfer to a wire cooling rack to cool completely. Enjoy!