Overnight Croissant Breakfast Casserole Recipe tastes buttery and custardy with crisp, golden edges and pockets of savory cheese and sausage. It suits holiday mornings, weekend brunch, or meal prep for guests, and it takes about 15 minutes prep, 35 to 40 minutes bake, plus an overnight chill for a total of about 9 hours. I baked a pan last weekend after a sunrise walk, and my family hovered like seagulls at a beach picnic.
Why You Should Try This Overnight Croissant Breakfast Casserole Recipe
Overnight Croissant Breakfast Casserole Recipe delivers bakery-level croissant flavor without early morning fuss. You assemble it at night, then you slide it into the oven while the coffee brews. The custard soaks in, the cheese melts, and the croissants puff into a rich, savory pie that feels special.
This casserole also handles swaps like a champ. You can use ham or sausage, cheddar or Gruyère, and veggies like spinach or peppers. It feeds a crowd and still tastes great as leftovers.
Ingredients You’ll Need
- 6 large croissants, preferably day-old, torn into big chunks
- 8 large eggs
- 2 cups whole milk, or use 1 cup whole milk plus 1 cup half-and-half for extra richness
- 1 cup half-and-half, or use all whole milk for a lighter custard
- 1.5 cups shredded cheese, cheddar or Gruyère both work well; pre-shredded saves time
- 1 cup cooked breakfast sausage or diced ham; use cooked mushrooms or spinach for a meat-free version
- 1/2 cup finely chopped onion or shallot
- 1/2 cup diced bell pepper, optional
- 1 teaspoon Dijon mustard
- 1 teaspoon kosher salt
- 1/2 teaspoon black pepper
- 1/4 teaspoon garlic powder
- 1/4 teaspoon smoked paprika, optional
- 2 tablespoons chopped chives or parsley, plus more for garnish
- 1 tablespoon butter or cooking spray for the dish
Pantry shortcuts and notes:
- Store-bought bakery croissants work best. If they feel very fresh, toast the chunks for 5 minutes to dry them slightly.
- I like Gruyère for nutty flavor, but sharp cheddar melts beautifully and costs less.
- Use lactose-free milk and cheese if needed. You can also swap in turkey sausage.
Equipment:
- 9 by 13 inch baking dish
- Large mixing bowl and whisk
- Skillet for sausage or veggies
- Foil
- Cooling rack and knife for serving
How to Make Overnight Croissant Breakfast Casserole
- Prep: 15 minutes
- Cook: 35 to 40 minutes
- Total: about 9 hours, including overnight chill
- Grease a 9 by 13 inch baking dish. Tear croissants into large chunks and spread them evenly in the dish.
- Cook sausage in a skillet until browned, then drain. Sauté onion and bell pepper in the same skillet until tender. Scatter sausage and veggies over the croissant pieces.
- Whisk eggs, milk, half-and-half, Dijon, salt, pepper, garlic powder, and smoked paprika in a large bowl until smooth. Stir in most of the cheese, saving a handful for topping.
- Pour the custard over the croissants. Press the top pieces gently so the liquid soaks in. Sprinkle the remaining cheese on top.
- Cover tightly with foil and chill in the fridge for at least 8 hours and up to 24 hours.
- Heat the oven to 350°F. Uncover the casserole and bake on the center rack for 35 to 40 minutes until the center feels set and the top looks golden. If the top browns too fast, tent loosely with foil for the last 10 minutes.
- Let the casserole rest for 10 minutes. Shower with chives or parsley, slice, and serve warm.
Tips & Tricks
- Use day-old croissants or lightly toast fresh ones for 5 minutes to prevent sogginess.
- Keep croissant chunks large so they trap custard and hold texture.
- Balance add-ins: aim for about 1 to 1.5 cups total mix-ins per pan.
- Need a lighter pan? Swap half the half-and-half with milk and use turkey sausage.
- Want a vegetarian version? Skip meat and add sautéed mushrooms, spinach, or roasted broccoli.
- For extra crisp edges, move the dish to the top rack for the last 5 minutes.
- For a touch of heat, stir a pinch of red pepper flakes into the custard.
What to Serve with Overnight Croissant Breakfast Casserole
This rich casserole pairs well with fresh fruit salad or a simple arugula salad with lemon vinaigrette. I also like crispy bacon or smoked salmon on the side for contrast. Offer hot sauce for spice lovers, plus coffee and orange juice for a classic brunch spread.
Make-Ahead and Storage
Assemble the casserole up to 24 hours ahead and chill covered. After baking, store leftovers covered in the fridge for 3 to 4 days. For the freezer, wrap the unbaked, assembled casserole tightly and freeze for up to 2 months, then thaw in the fridge overnight and bake as directed. You can also freeze baked portions for up to 2 months; reheat covered at 325°F for 15 to 20 minutes or microwave slices and finish in a toaster oven to crisp the top.
Nutrition Information
I based these estimates on 8 servings with sausage and cheddar: about 510 calories, 33 g fat, 30 g carbs, 22 g protein, 2 g fiber, and 820 mg sodium per serving. Actual numbers will vary with your mix-ins and cheese choice.
Overnight Croissant Breakfast Casserole
Ingredients
Instructions
- Cook sausage in a skillet over medium heat until browned; drain excess fat.
- In a greased baking dish, layer half of the croissant cubes, then half of the cooked sausage and cheese.
- Repeat layers with remaining croissants, sausage, and cheese.
- In a bowl, whisk together eggs, milk, salt, and pepper.
- Pour egg mixture evenly over casserole.
- Cover and refrigerate overnight.
- Preheat oven to 350°F (175°C).
- Bake casserole uncovered for 45 minutes or until set and golden on top.
- Let cool slightly before serving.