Preheat your oven to 350°F (175°C) and grease a 9x13-inch baking dish with butter or non-stick spray.

Cut the bread into cubes, aiming for approximately 1-inch pieces, and spread half in the bottom of the greased baking dish.

Layer half of the ham over the bread cubes, followed by half of the shredded Swiss cheese.

In a large bowl, whisk together the eggs, milk, maple syrup, mustard, salt, and pepper until well combined.

Pour half of the egg mixture over the layered bread, ham, and cheese, pressing down gently with a spatula.

Repeat the layering process with the remaining bread, ham, cheese, and the rest of the egg mixture.

Cover with aluminum foil and bake for 30 minutes, then remove the foil and bake for an additional 15-20 minutes until set and golden brown.

Let the casserole cool for about 10 minutes before serving.