Overnight Croissant and Egg Breakfast Casserole

This Croissant Egg Bake pairs flaky, buttery croissants with a fluffy, savory egg custard, sausage and vegetables to create a crowd-pleasing breakfast casserole. It’s an ideal brunch recipe for holiday mornings, potlucks, or any time you want an easy, make-ahead meal. Whether you’re using day-old croissants or fresh bakery croissants, the rich texture of the pastry soaks up the egg mixture while remaining tender around the edges.

This recipe brings together the best of breakfast flavors. Croissants add buttery layers and a slightly sweet note that balances the savory sausage and sautéed vegetables. The result is a comforting casserole that slices neatly and reheats well, making it practical for feeding a crowd or enjoying leftovers throughout the week.

Top tips for success

Use about 4 large croissants broken into chunks to cover the bottom of a 9×13 baking dish. If your croissants are small, increase the quantity so the base is well covered. The croissant pieces act like bread in a strata, absorbing the egg mixture and holding the filling together.

Breakfast sausage adds bold flavor here, but you can easily substitute cooked bacon, ham, or turkey sausage to suit dietary preferences. Similarly, swap the bell peppers for mushrooms, spinach, broccoli, or any vegetables you need to use up—this recipe is flexible.

For cheese, sharp cheddar is delicious and melts nicely. Gruyère or a mild fontina would also work well if you want a different flavor profile.

Croissant Egg Bake Recipe

Author: Emily Richter

Prep: 25 mins • Cook: 40 mins • Total: 1 hr 5 mins • Servings: 9

Make breakfast exciting with this croissant egg bake—flaky croissants, savory sausage, sautéed vegetables and a silky egg custard finished with melted cheddar. It’s an excellent option for brunch, holiday mornings, or meal-prepping breakfasts for the week.

Ingredients

• 4 large croissants, sliced into chunks
• 1 lb. breakfast sausage
• ½ white onion, diced
• 3 cloves garlic, minced
• 2 bell peppers, diced
• 3 teaspoons Italian seasoning
• 1 teaspoon sea salt, divided
• ¼ teaspoon ground black pepper
• 10 large eggs
• ½ cup cottage cheese
• ¼ cup half and half
• ½ cup cheddar cheese, shredded

Instructions

1. Preheat the oven to 350ºF (175ºC) and spray a 9×13-inch baking dish with cooking spray.
2. Place the croissant chunks evenly in the prepared baking dish so they form a base layer.
3. Heat a large skillet over medium-high heat and add the breakfast sausage. Break it into small pieces and cook until it begins to brown but is not fully cooked through.
4. Add the diced onion, minced garlic, diced bell peppers, 1 tablespoon olive oil, Italian seasoning, and ½ teaspoon salt to the skillet with the sausage. Sauté for about 5 minutes, or until the peppers start to soften and the onions are translucent.
5. Transfer the sausage and vegetable mixture to the baking dish and gently toss with the croissant pieces to distribute evenly.
6. In a large bowl, whisk together the eggs, remaining ½ teaspoon salt, ground black pepper, cottage cheese, and half and half until smooth. Pour the egg mixture over the croissants and sausage in the baking dish, stirring lightly to combine.
7. Cover the dish and bake for 30 minutes. Remove the cover, sprinkle the shredded cheddar over the top, and bake uncovered for an additional 10–15 minutes, or until the eggs are fully set and the cheese is golden.
8. Remove from the oven and let the casserole rest for 10 minutes before slicing and serving.

Overnight Casserole Instructions

This dish is perfect for preparing the night before. Assemble up to step 6, cover the baking dish, and refrigerate overnight. In the morning, remove the casserole from the fridge and let it sit at room temperature for about 30 minutes, then bake as directed. This makes holiday mornings effortless—just bake, slice and serve.

Storage Directions

Store leftovers in an airtight container in the refrigerator for up to 3 days. To reheat, warm individual portions in the microwave for 1–2 minutes or until heated through, or reheat in a 350ºF oven until warmed.

Tips & Notes

• Adjust the number of croissants depending on size; small croissants will require more to cover the pan.
• Swap or add vegetables to taste—mushrooms, spinach, or broccoli are great options.
• Try different cheeses: cheddar for sharp flavor, or gruyère for a nuttier profile.

Nutrition

Nutrition information is an estimate and should be used as a guideline. Per serving:

• Calories: 385 kcal
• Carbohydrates: 16 g
• Protein: 19 g
• Fat: 27 g
• Fiber: 2 g
• Sugar: 5 g

Nutrition information is automatically calculated and should be treated as an approximation.

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