Irresistible Overnight Croissant Breakfast Casserole
This Overnight Croissant Breakfast Casserole is a rich, comforting breakfast that’s perfect for holidays, brunch, or busy mornings. Buttery croissants soak up a creamy egg custard, while savory sausage and melted cheese make every bite warm, flaky, and satisfying. Best of all, it’s prepped the night before and baked fresh in the morning with almost no effort.
Ingredients
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5 large croissants (preferably day-old), torn into large chunks
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1 lb (450 g) ground sausage, cooked and drained
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1 cup (120 g) shredded cheddar cheese
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6 large eggs
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2 cups (475 ml) whole milk
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1 teaspoon salt
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½ teaspoon black pepper
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½ teaspoon garlic powder
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½ teaspoon onion powder
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Fresh parsley, chopped (optional, for garnish)
Optional Add-Ins & Swaps
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Cooked turkey, chicken, or plant-based sausage
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Swiss, Monterey Jack, or mozzarella cheese
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Sautéed spinach, mushrooms, or bell peppers
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A dash of hot sauce or red pepper flakes for heat
Instructions
Grease a 9×13-inch baking dish with butter or cooking spray.
Spread the torn croissants evenly in the dish.
Top with the cooked sausage and sprinkle the shredded cheese over everything.
In a large bowl, whisk together the eggs, milk, salt, pepper, garlic powder, and onion powder.
Pour the mixture evenly over the croissant layers.
Gently press down so the croissants absorb the custard.
Cover the dish with foil and refrigerate for at least 6 hours or overnight.
Preheat the oven to 350°F (175°C).
Uncover the casserole and bake for 40–45 minutes, until golden brown and set in the center.
Let rest for 10 minutes before garnishing with parsley and serving.
Notes
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Use day-old croissants for the best texture—they absorb the custard without becoming mushy.
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Don’t skip the rest time after baking; it helps the casserole set and slice cleanly.
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Customize freely—this recipe works well with vegetables, different cheeses, or leftover meats.
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Make it lighter by using half-and-half or 2% milk instead of whole milk.