Combine all ingredients for the sauce and mix well.
Spread 1 tablespoon of sauce on each of 3 slices of bread. Top with sliced apples, ham and cheese. Place remaining slices of bread on top of each sandwich.
Brush the tops of each sandwich with melted butter and sprinkle with salt and pepper.
Place sandwiches butter side down on hot grill pan or panini press and brush remaining side with butter.
Cook until both sides are golden brown and cheese is melted.
Serve with remaining sauce.