Ingredients:

2 eggs, separated
1 1/2 cups milk
1/2 cup melted butter
2 cups sifted all-purpose flour
2 teaspoons baking powder
1/2 teaspoon salt
1 tablespoon sugar
1 cup fresh or frozen blueberries, rinsed

In a small mixing bowl, beat egg whites until stiff; set aside. Beat egg yolks; add milk and melted butter. Sift dry ingredients together; add egg yolk mixture and mix until smooth and fold in blueberries. Gently fold in beaten egg whites. Bake in a hot waffle iron. Makes about 6 blueberry waffles.

Source: about.com