Turn oven to 425°F.
Put butter in a 9x13 baking dish and place it in the oven while it's preheating to melt the butter. Remove once butter is melted.
Slice bread to sandwich style slices (any thickness you prefer)
In a shallow dish, combine bread crumbs & parmesan.
In a separate dish, beat the 2 eggs with the milk
Dip one side of each piece of bread in the egg mixture, then coat it well in the crumb mixture, and set it in the buttered pan (coated side down)
Once pan is full, top each slice of bread with a slice of cheese and 2-3 slices of meat, then top with an additional slice of cheese.
Continue the pattern of dipping the remaining slices of bread in the egg mixture and then coating with bread crumbs to create the tops of the sandwiches. Place the remaining slices (coated side up) on top of each sandwich in the pan.
Bake for 5-8 minutes, then remove the pan from the oven, use a spatula to flip the sandwich, then bake for another 5-8 minutes, or until both sides are golden brown.
Optional: if you'd like your sandwiches even crispier, broil for 1-2 minutes. Watch very carefully so they don't burn!
Serve with warm marinara sauce for dipping!