Sandwich French Toast Casserole

Preheat oven to 350 degrees F (175 degrees C). Spray the inside of a 9x13-inch casserole dish with cooking spray.

Spread butter on one side of each bread slice; top each bread slice with 2 slices ham and 1 slice Swiss cheese. Arrange open-faced sandwiches in the prepared casserole dish overlapping them to fit.

Whisk milk eggs Worcestershire sauce mustard powder salt and pepper together in a bowl; pour milk mixture over the open-faced sandwiches. Allow milk mixture to soak in for at least 15 minutes.

Bake in the preheated oven until eggs are set and casserole is cooked through about 20 minutes.