Heat oven to 375°F. Line 12 muffin cups with baking liners. In a large bowl, combine baking mix, oats, and 1/2 cup sugar. In a medium bowl, beat together the milk, egg, and vegetable oil.
Stir milk mixture into dry baking mixture just to combine. Add blueberries and stir. Using an ice-cream scoop, place batter in muffin cups. Sprinkle tops with remaining 1 tablespoon sugar.
Bake in oven for 17 minutes or until a toothpick inserted into center of a muffin comes out clean.