Using your spray oil, give the waffle maker a good coating. Add the batter. Sprinkle a few blueberries on top of the batter. Close the waffle maker's lid and cook until the steam stops or the ready light goes on. Note: Even though the ready light went on with my waffle maker, I let them bake a bit longer, I like my waffles crisp. Make sure you check them if you do this as you don't want them to burn.