In the bowl of an electric mixer fitted with the paddle attachment, combine the first 8 ingredients.
Preheat a waffle iron. When it is hot, spray its surface lightly with the cooking spray or brush it with the butter.
Fill a medium-size ladle with batter and pour it onto the waffle iron. Cook until the waffle is golden brown and a toothpick inserted into the middle comes out clean, approximately 3 to 5 minutes. Serve hot with maple syrup and butter or fresh berries.