Creating the Monte Cristo Breakfast Casserole is simple if you follow these steps:

1. Preheat the Oven: Begin by preheating your oven to 350°F (175°C).
2. Prepare the Bread: Cut the bread into cubes and place them in a greased 9×13-inch baking dish. Spread them out evenly.
3. Mix the Eggs: In a large bowl, whisk together the eggs, milk, Dijon mustard, maple syrup, vanilla extract, salt, and pepper until well combined.
4. Layer the Ingredients: Pour half of the egg mixture over the bread cubes. Then, sprinkle the ham, turkey, and both cheeses evenly over the bread.
5. Add the Remaining Egg Mixture: Pour the remaining egg mixture over the top, ensuring that all the bread is soaked well.
6. Press Down: Gently press down on the bread to help it absorb the egg mixture.
7. Let It Rest: Allow the casserole to sit for about 15-20 minutes to soak up the flavors.
8. Bake: Place the baking dish in the preheated oven and bake for 45-50 minutes, or until the casserole is set and golden on top.
9. Cool: Once baked, allow the casserole to cool for about 5 minutes before slicing.
10. Serve: Slice into squares and serve warm, dusted with powdered sugar and accompanied by fresh berries if desired.

These straightforward steps will guide you in creating this incredible breakfast casserole with ease!