Step 1

Preheat the oven to 350°F, and generously coat two waffle pans with nonstick cooking spray.

Step 2

In a medium bowl, whisk together the flour, baking soda, baking powder, and salt. In a separate bowl, whisk together the butter, egg whites, vanilla, and maple syrup. Add in the Greek yogurt, stirring until no large lumps remain. Stir in the vinegar and milk. Alternate between adding the flour mixture and water, beginning and ending with the flour mixture, and stirring just until incorporated. (For best results, add the flour mixture in 4 equal parts.) Gently fold in the blueberries.

Step 3

Divide the batter between the prepared waffle pans, and spread the batter out with a spatula. (It doesn’t spread on its own!) Bake at 350°F for 13-16 minutes or until the centers feel firm to the touch and a toothpick inserted into the center comes out clean or with a few crumbs attached. Cool in the pan for 10 minutes before transferring to a wire rack.

Step 4

FOR WAFFLES WITH CRISP OUTSIDES: Let the waffles cool completely to room temperature. Toast individual waffles in a toaster oven until deep golden brown on the outside.