Place 4 slices of bread on a work surface. Layer each slice with a slice of ham, a slice of turkey, and a slice of Swiss cheese. Top with the remaining slices of bread.
In a shallow bowl, whisk together the eggs, milk, salt, and pepper.
Heat butter in a large skillet over medium heat.
Dip each sandwich into the egg mixture, coating both sides.
Place the sandwiches in the skillet and cook until golden brown, about 3-4 minutes per side.
Remove from the skillet and dust with powdered sugar.
Serve warm with raspberry jam or maple syrup for dipping.
Enjoy!