Preheat oven to 400 degrees.Place all ingredients into a mixer.Stop the mixer a few times and scrape the sides to make sure everything blends together evenly.Pour batter into greased muffin tins or use cupcake liners.Optional: Add a few chocolate chips or blueberries to the top of each muffin and lightly stir them in with a toothpick.Bake for 10-15 minutes, or until tops of muffins turn golden brown.