Creating Croissant Breakfast Casserole can be straightforward if you follow these simple steps:

1. Preheat Oven: Preheat your oven to 350°F (175°C) and grease a 9×13 inch baking dish.
2. Prepare Croissants: Tear the croissants into bite-sized pieces and place them evenly in the greased baking dish.
3. Whisk Eggs: In a large bowl, whisk together the eggs, milk, salt, black pepper, garlic powder, and onion powder until well combined.
4. Add Cheese and Meat: Stir in the shredded cheese and diced ham or sausage, if using. Mix well.
5. Combine Mixtures: Pour the egg mixture over the croissant pieces, ensuring they are evenly coated. Gently press down to submerge any dry pieces.
6. Add Vegetables: Sprinkle diced bell peppers or spinach over the top, if desired. Give it a gentle stir to distribute.
7. Bake: Place the casserole in the preheated oven and bake for 40-45 minutes, or until the top is golden brown and a knife inserted comes out clean.
8. Cool: Remove from the oven and let it cool for 10-15 minutes before serving.
9. Garnish: If desired, sprinkle fresh herbs over the top for an added touch of color.

Following these steps will help you create an incredible Croissant Breakfast Casserole that everyone will love!