Overnight Croissant Breakfast Casserole – Easy, Make-Ahead, & Delicious

Start your mornings stress-free with this Overnight Croissant Breakfast Casserole! Flaky, buttery croissants are combined with savory sausage, creamy eggs, and melty cheese to create a breakfast that’s irresistible. Perfect for weekends, holidays, or busy mornings, this casserole can be prepared the night before and baked fresh in the morning.

Why You’ll Love This Recipe

• Make-Ahead Convenience: Assemble the casserole the night before and bake in the morning.
• Rich, Flavorful Breakfast: Buttery croissants, savory sausage, and gooey cheese create a comforting, satisfying dish.
• Customizable: Add vegetables, alternate meats, or different cheeses to make it your own.
• Crowd-Pleaser: Ideal for family gatherings, brunches, or feeding a hungry crowd.
• Kid-Friendly: Familiar flavors that everyone will enjoy.
• Versatile: Serve for breakfast, brunch, or a light dinner.
• Protein-Packed: Eggs and sausage provide a hearty, energizing start to the day.

Ingredients

Casserole Base:

• 6 large croissants, cut into pieces
• 1 lb breakfast sausage, cooked and crumbled
• 2 cups shredded cheddar cheese

Egg Mixture:

• 6 large eggs
• 2 cups milk
• 1 teaspoon dry mustard
• ½ teaspoon salt
• ¼ teaspoon black pepper

Instructions

1. Prepare the Dish: Grease a 9×13-inch baking dish. Arrange croissant pieces evenly in the dish.
2. Add Sausage & Cheese: Sprinkle cooked sausage and shredded cheese over the croissants.
3. Make the Egg Mixture: In a large bowl, whisk eggs, milk, dry mustard, salt, and pepper until combined.
4. Assemble: Pour the egg mixture over the croissant, sausage, and cheese layers. Press lightly so croissants soak up the custard.
5. Refrigerate: Cover and refrigerate overnight (or at least 2 hours).
6. Bake: Preheat oven to 350°F (175°C). Remove casserole from fridge and let sit at room temperature while oven heats. Bake uncovered for 40–45 minutes, until golden brown and custard is set.
7. Serve: Let cool a few minutes, then slice and serve warm.

Pro Tips

• Layer Evenly: Ensure croissants, sausage, and cheese are evenly distributed for consistent flavor.
• Overnight Soak: Allowing croissants to soak in the egg mixture overnight creates a rich, custardy texture.
• Serve Warm: This casserole tastes best straight from the oven.

Variations

• Vegetarian: Replace sausage with sautéed vegetables like bell peppers, spinach, or mushrooms.
• Spicy: Add diced jalapeños or a dash of hot sauce to the egg mixture.
• Cheese Options: Swap cheddar for Swiss, Gruyère, or mozzarella for a different flavor profile.

Storage & Freezing

• Refrigerator: Store leftovers in an airtight container for up to 3 days.
• Freezer: Freeze unbaked casserole for up to 2 months; thaw overnight in the fridge before baking.
• Reheating: Warm in the oven or microwave.

Serving Suggestions

Serve with fresh fruit, roasted potatoes, or a light green salad. Pair with coffee or fresh juice for a complete, hearty breakfast