Blend all the ingredients together with a whisk or in a blender. Note: I found that I needed to add more liquid to make a semi-runny batter. It is extremely dry here and the batter was quite thick at first. Once you are satisfied with the batter consistency, let it sit for 5 minutes.
Heat the waffle maker according to the manufacturer's directions. Do not oil at this point, wait until the waffle maker is heated up first.
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.
Repeat with the remaining batter. Note: If you use frozen blueberries like I did, thaw them in the microwave for a minute or two until the freezing comes out and the moisture is expelled. I put mine in a sieve and let them drain for a few minutes. This ensured the excessive moisture is out of them. Also be aware that the froze berries might demand that you cook your waffles a little longer. Remove the waffles when done and drizzle with maple syrup. So good!