Relevant beer types:  Stout beer

Ingredients:  
    1-1/2 cups flour
    1 Tablespoon baking powder
    1/2 teaspoon salt
    3 eggs, separated
    1/2 cup milk
    1/2 cup Stout
    2 Tablespoons bourbon
    1 cup mashed cooked yams, cooled
    2 Tablespoons melted butter
    Pinch each nutmeg, cardamom, and ginger

Preparation:
Sift together the flour, baking powder, and salt. Beat the egg yolks and mix them with the milk, Stout, bourbon, yams, melted butter, and spices. Beat the egg whites until they form soft peaks and fold them into the batter. Cook like ordinary waffles, following your waffle iron instructions. Pour on plenty of good-quality maple syrup.

Preparation Time:  5 min

Yield:  6 waffles with enough for seconds

Cooking Time:  30 min

Source:  http://homecooking.about.com