Breakfast & Brunch

Overnight Croissant Breakfast Casserole

Name: Overnight Croissant Breakfast Casserole
Prep time: 15 min
Cook time: 50 min
Total time: 1 h 5 min
Cuisine: American
Ingredients: 6 large croissants, torn into pieces; 6 large eggs; 2 cups milk; 1 cup shredded cheese (e.g., Gruyère or cheddar); 1 cup cooked and crumbled breakfast sausage or diced ham; 1/2 cup diced onion; 1/2 cup diced bell pepper; 1 teaspoon salt; 1/2 teaspoon black pepper; 1/2 teaspoon garlic powder; 1/2 teaspoon dried thyme; Fresh parsley for garnish (optional)

Chef Olivia

December 24, 2025
4 min read

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why make this recipe

This casserole is easy and makes mornings calm. You make it the night before and bake it in the morning. It uses croissants for a rich, flaky base and holds flavor well. If you like simple make-ahead breakfast ideas, try this type of dish like the crack breakfast casserole for more ideas.

introduction

Overnight Croissant Breakfast Casserole is a simple baked egg dish. Croissant pieces soak in an egg-and-milk mix overnight. In the morning you bake it until golden. It is warm, cheesy, and good for family breakfasts or a small brunch.

how to make Overnight Croissant Breakfast Casserole

Tear croissants and place them in a dish. Whisk eggs, milk, and seasonings. Pour the mix over the croissants and add cheese and cooked meat. Cover and chill overnight so the croissants soak up the egg. Bake the next morning until set.

Ingredients :

6 large croissants, torn into pieces
6 large eggs
2 cups milk
1 cup shredded cheese (e.g., Gruyère or cheddar)
1 cup cooked and crumbled breakfast sausage or diced ham
1/2 cup diced onion
1/2 cup diced bell pepper
1 teaspoon salt
1/2 teaspoon black pepper
1/2 teaspoon garlic powder
1/2 teaspoon dried thyme
Fresh parsley for garnish (optional)

Directions :

Grease a 9×13 inch baking dish. Spread croissant pieces evenly in the dish.
In a large bowl, whisk together eggs, milk, salt, pepper, garlic powder, and thyme.
Pour the egg mixture over the croissants. Top with cheese, sausage/ham, onion, and bell pepper.
Cover the dish with plastic wrap or foil and refrigerate overnight.
In the morning, preheat the oven to 350°F (175°C).
Bake uncovered for 45-50 minutes or until the casserole is set and golden brown.
Let it cool for a few minutes, garnish with parsley if desired, and serve warm.

Overnight Croissant Breakfast Casserole

how to serve Overnight Croissant Breakfast Casserole

Cut into squares and serve warm. Add a green salad or fruit on the side for a full meal. It goes well with coffee or tea and simple sides from a breakfast and brunch menu.

how to store Overnight Croissant Breakfast Casserole

Let cool to room temperature. Cover and keep in the fridge for up to 3 days. Reheat slices in the oven at 325°F (160°C) for 10–15 minutes or until warm. For longer storage, freeze portions in a sealed container for up to 1 month. Thaw in the fridge before reheating.

tips to make Overnight Croissant Breakfast Casserole

Use day-old croissants so they soak the egg better.
Mix meats and vegetables you like. Cook raw vegetables first so they are soft.
Do not overfill the dish; leave a little space so the center can cook.
Let it rest 5–10 minutes after baking so slices hold together well.

variation (if any)

Make it vegetarian: skip the meat and add mushrooms or spinach.
Swap cheese types: use Swiss, mozzarella, or pepper jack.
Add herbs: fresh chives, rosemary, or basil can lift the flavor.
Make single-serve: bake in ramekins for individual portions.

FAQs

Q: Can I use other bread instead of croissants?
A: Yes. Use brioche or French bread, but croissants give a flaky, rich texture.

Q: Can I prepare it the same day?
A: Yes. If short on time, let croissants soak for 1–2 hours at room temperature before baking.

Q: How do I know it is fully cooked?
A: The center should be set and not jiggle. A knife inserted in the middle should come out mostly clean.

Q: Can I change the meat type?
A: Yes. Use bacon, ham, or cooked sausage pieces to match your taste.

Q: Is it safe to leave eggs overnight?
A: Yes if the dish stays covered in the fridge. Keep it chilled until baking.