Ham-and-Cheese Waffles

Preparation Preheat oven to 300°F. Heat waffle iron until very hot. Whisk 1 3/4 cups flour, 1 tablespoon sugar, 2 teaspoons baking powder, 1 teaspoon baking soda, and 1 teaspoon kosher salt in a large bowl. Using an electric mixer, beat 3 large egg whites in a medium bowl until medium-soft peaks form. Whisk 3 large egg yolks, 1 cup (2 sticks) melted butter, 1 cup buttermilk, and 3/4 cup soda water in a medium bowl; gradually whisk into dry ingredients. Fold in egg whites. Coat waffle iron with nonstick vegetable oil spray. Pour batter onto iron, spreading it into corners (amount of batter needed will vary according to machine). Scatter 1 rounded tablespoon thin strips of ham and 1 tablespoon shredded sharp white cheddar over each waffle. Cook until golden brown and cooked through. Transfer to a baking sheet; keep waffles warm in oven between batches. Serve with butter and warm maple syrup.

Preparation Preheat oven to 300°F. Heat waffle iron until very hot. Whisk 1 3/4 cups flour, 1 tablespoon sugar, 2 teaspoons baking powder, 1 teaspoon baking soda, and 1 teaspoon kosher salt in a large bowl. Using an electric mixer, beat 3 large egg whites in a medium bowl until medium-soft peaks form. Whisk 3 large egg yolks, 1 cup (2 sticks) melted butter, 1 cup buttermilk, and 3/4 cup soda water in a medium bowl; gradually whisk into dry ingredients. Fold in egg whites. Coat waffle iron with nonstick vegetable oil spray. Pour batter onto iron, spreading it into corners (amount of batter needed will vary according to machine). Scatter 1 rounded tablespoon thin strips of ham and 1 tablespoon shredded sharp white cheddar over each waffle. Cook until golden brown and cooked through. Transfer to a baking sheet; keep waffles warm in oven between batches. Serve with butter and warm maple syrup.