Creating the Overnight Croissant Breakfast Casserole is a breeze with these simple steps:

1. Prepare the Croissants: Cut the croissants into bite-sized pieces and place them in a greased 9×13-inch baking dish.

2. Mix Eggs and Milk: In a large bowl, whisk together the eggs and whole milk until well combined. Season with salt, black pepper, garlic powder, and onion powder.

3. Add Cheese and Protein: Stir in the shredded cheese and cooked ham or sausage, if using. Add the chopped spinach for a pop of color and nutrition.

4. Combine Mixtures: Pour the egg mixture evenly over the croissant pieces, ensuring that all pieces are well-coated.

5. Press Down: Gently press down on the croissant pieces to help them absorb the egg mixture.

6. Cover and Chill: Cover the baking dish with plastic wrap and refrigerate overnight. This allows the croissants to soak up the egg mixture.

7. Preheat Oven: The next morning, preheat your oven to 350°F (175°C).

8. Bake: Remove the plastic wrap and bake the casserole for 30-35 minutes, or until the egg is set and the top is golden brown.

9. Cool Slightly: Once baked, allow the casserole to cool for about 5-10 minutes before serving.

10. Garnish and Serve: Optionally, garnish with fresh herbs before slicing and serving.

These steps will guide you in effortlessly creating the Overnight Croissant Breakfast Casserole, ensuring a delicious and satisfying breakfast experience.