These waffles are so good! I used the America's Test Kitchen recipe for buttermilk waffles and just added some green food coloring to make it green for St. Patty's. The batter is very thick and you have to use a heat resistant spatula to spread it out on the waffle iron, but don't be tempted to add more liquid, the batter is meant to be thick - it's what makes them so fluffy and good. I'm going to double the recipe next time because this recipe only makes about 5 thick waffles.
Awful Waffles (buttermilk waffles dyed green)
2 cups all purpose flour
1 teaspoon salt
1/2 teaspoon baking soda
2 large eggs, separated
pinch of cream of tartar
4 tablespoons butter, melted
1 3/4 cups buttermilk
6 drops green food coloring
Heat waffle iron according to manufacturer's instructions.
Whisk together flour, salt, and baking soda in a large bowl. In a separate bowl whisk together egg yolks, butter, and then the buttermilk and the green food coloring if adding. Beat the egg white and pinch of cream of tartar with an electric mixer until stiff peaks form - about a minute. Make a well in the center of the dry ingredients, pour the buttermilk mixture into the well and whisk very gently until the buttermilk mixture is just incorporated. Toward the end of mixing fold in the whipped egg whites into the batter.
Following the manufacturer's instructions, spread the appropriate amount of batter onto the waffle iron (because it is thick you will probably need to spread out the batter with a heat-resistant spatula) and cook until golden brown.