Preheat oven to 400°. Combine 1/4 cup sugar, 2 1/2 tablespoons flour, and cinnamon in a bowl; cut in butter with a pastry blender or fingertips until mixture is crumbly. Set aside.
Combine 1 1/4 cups flour and next 5 ingredients in a medium bowl until well blended; make a well in center of mixture. Combine egg, milk, and oil; add to cornmeal mixture, stirring just until moistened.
Combine blueberries, 1 tablespoon flour, and 1 tablespoon sugar, tossing gently to coat. Fold blueberry mixture into batter. Spoon batter evenly into 10 (2 1/2-inch) muffin cups coated with cooking spray; sprinkle cinnamon mixture over batter. Bake muffins at 400° for 20 minutes or until lightly browned and muffins spring back when touched lightly in center. Remove from pans immediately.