Pumpernickel Waffles

Name: Pumpernickel Waffles
Ingredients: 3 cups whole milk; 1/4 cup yellow cornmeal; 1/4 cup unsulphured molasses; 1/2 ounce unsweetened chocolate, coarsely chopped; 2 teaspoons finely chopped caraway seeds; 1 teaspoon salt; 3 large egg yolks, lightly beaten; 1 tablespoon active dry yeast; 1 1/2 cups all-purpose flour; 3/4 cup whole wheat flour; 3/4 cup rye flour; 1 cup mashed potatoes, at room temperature; 1 stick (4 ounces) unsalted butter, melted; 3 large egg whites; 2 tablespoons sugar