In a large bowl, combine the biscuit mix and 1/2 cup sugar. Whisk the egg and sour cream; stir into dry ingredients just until moistened. Fold in blueberries.
Fill greased or paper-lined muffin cups half full. Combine lemon peel and remaining sugar; sprinkle over batter. Bake at 400 degrees for 20-25 minutes or until a toothpick comes out clean. Cool for 5 minutes before removing from pan to a wire rack. Serve warm, makes 1 dozen. (If using frozen blueberries, do not thaw before adding to batter).