Place turkey and Swiss cheese on one slice of bread and ham and American cheese on another slice of bread. Place third slice in-between and secure the triple-decker sandwich in the corners with toothpicks.
Place egg in mixing bowl, add water and beat together. Add salt, sugar, flour, and baking powder. Beat batter until smooth.
Dip sandwich in batter and carefully cover all the sides and surface. Carefully place in hot oil and fry until golden. When the sandwich has turned a warm gold color remove it from the hot oil and place it on a paper towel. Let cool for a few minutes before removing the toothpicks. Before serving slice into fourths and sprinkle with powder sugar.
Serve with raspberry preserves, pickle garnish, and your favorite French fried potatoes.