Introduction

If you’re looking for a hearty, crowd-pleasing morning dish that doesn’t require a morning hustle, this Overnight Croissant Breakfast Casserole is your new best friend. I’ve made this countless times for holiday mornings, brunch potlucks, and lazy Sundays, and it never disappoints. With buttery croissants, savory sausage, fluffy eggs, and melty cheese baked into one cozy dish, this casserole is what I like to call “a hug on a plate.” It’s the kind of recipe that gives you a luxurious start to the day—without waking up at the crack of dawn.

The best part? You prep everything the night before, pop it in the fridge, and simply bake it the next morning. Whether you’re feeding a family or hosting brunch for friends, this dish brings gourmet-level comfort to your table with minimal effort. If you love breakfast casseroles but want something a little elevated—something with that golden, flaky croissant magic—Overnight Croissant Breakfast Casserole is perfect fit for you. Trust me, once you try this, it’s going to earn a permanent spot in your breakfast rotation.

Perfect for:

Holiday mornings when you want something special without the stress.
Weekend brunches with friends or family.
Meal prepping an easy breakfast for busy weekdays.
Using up day-old croissants in the most delicious way.
Potluck or church breakfast casseroles everyone will rave about.

Why You will Love this Recipe

Make-Ahead Convenience: All the prep happens the night before, so you can actually relax in the morning. No chopping, cracking, or whisking while you’re half asleep!
Golden, Buttery Croissants: The croissants soak up the egg mixture while keeping their flaky, rich texture. Way more flavorful than traditional bread.
Savory and Satisfying: With sausage, cheese, and eggs in every bite, it’s a full, balanced breakfast in one dish.
Perfect for a Crowd: This recipe easily feeds 8–10 hungry guests and can be doubled for larger gatherings.
Customizable: You can swap out the sausage, add veggies, or use different cheeses depending on what you love.

Preparation and Cooking time

Prep Time: 20 minutes
Chill Time: 8 hours (overnight)
Cook Time: 45 minutes
Total Time: 9 hours 5 minutes
Servings: 8–10
Calories: 420 per serving (approximate)

Ingredients:

6 large butter croissants (preferably day-old)
1 lb breakfast sausage (or bacon/ham)
1 ½ cups shredded sharp cheddar cheese
1 cup shredded mozzarella cheese
8 large eggs
2 cups whole milk
½ cup heavy cream
1 tsp Dijon mustard
½ tsp garlic powder
½ tsp onion powder
Salt and pepper to taste
2 tbsp chopped chives or green onions (optional, for garnish)

Ingredient Highlights:

Croissants: Slightly stale croissants work best because they absorb the custard without falling apart. Buttery and flaky, they elevate this casserole beyond basic bread versions.
Sausage: Use your favorite breakfast sausage—pork, chicken, or turkey. I personally love a spicy sausage for extra flavor.
Cheese: Sharp cheddar adds tang and body; mozzarella brings the melty, gooey pull we all love.
Custard Base: A combo of eggs, milk, cream, and a touch of Dijon adds richness and structure.

Step-by-Step Instructions:

Brown the Sausage: In a skillet over medium heat, cook your sausage until fully browned. Drain excess fat and set aside to cool.
Tear the Croissants: Roughly tear the croissants into bite-sized chunks and layer them in a greased 9×13-inch baking dish.
Add the Sausage & Cheese: Sprinkle the cooked sausage evenly over the croissants, followed by the cheddar and mozzarella cheeses.
Make the Egg Mixture: In a large bowl, whisk together the eggs, milk, cream, Dijon, garlic powder, onion powder, salt, and pepper.
Pour the Custard: Slowly pour the egg mixture over the croissant mixture, making sure everything is evenly coated.
Cover & Chill: Cover the dish tightly with plastic wrap or foil and refrigerate overnight (at least 8 hours).
Bake in the Morning: Preheat oven to 350°F (175°C). Remove the casserole from the fridge and let it sit at room temp for 20 minutes. Bake uncovered for 45–50 minutes until golden and set in the middle.
Garnish & Serve: Let cool for 5 minutes, sprinkle with fresh chives, and serve warm.

Serving Suggestions:

With a side of fresh fruit or a citrusy fruit salad.
Paired with a light arugula salad and vinaigrette.
Served alongside crispy hash browns or roasted potatoes.
Drizzled with a little hot sauce or sriracha for a spicy kick.
Topped with a dollop of sour cream or Greek yogurt.

Additional Tips:

Don’t Skip the Chill: This overnight step is key—croissants need time to soak up the custard.
Avoid Overbaking: The center should be set but slightly jiggly. Overbaking can dry it out.
Use a Serrated Knife: It cuts through flaky croissants cleanly.
Customize It: Add spinach, bell peppers, or mushrooms for a veggie version.
Freezer Tip: Assemble and freeze unbaked, then thaw overnight before baking.

Recipe Variations:

Vegetarian Version
- Skip the sausage and bulk things up with a mix of sautéed mushrooms, fresh spinach, and diced bell peppers. These veggies bring a hearty texture and deep savory flavor that holds up beautifully against the rich eggs and melty cheese. It’s a wholesome, satisfying option for meatless mornings or brunches with vegetarian guests.
Spicy Southwest
- Kick up the flavor with bold Southwest flair. Swap in spicy chorizo sausage, use pepper jack cheese for an extra kick, and stir in a spoonful of canned diced green chiles. Add a sprinkle of cumin or smoked paprika for deeper warmth. Serve with a side of salsa or a dollop of sour cream for the full Tex-Mex breakfast experience.
Ham & Swiss
- Keep it classic with the timeless combination of diced ham and Swiss cheese. Gruyère also works wonderfully here for a nuttier depth. This variation has that cozy, deli-style charm and is especially delicious tucked into buttery croissants or fluffy brioche rolls.
Low-Carb Twist
- Watching carbs? No problem. Swap out the croissants for keto-friendly options like almond flour biscuits, low-carb sandwich thins, or cloud bread. You’ll still get all the rich, savory flavors of the original dish—just without the added carbs. Ideal for anyone following a ketogenic or low-carb lifestyle.
Caprese-Style
- Bring a burst of freshness to your breakfast with a Caprese-inspired version. Layer in halved cherry tomatoes, torn fresh basil, and creamy mozzarella. Drizzle with a touch of balsamic glaze just before serving for an Italian twist that’s vibrant, elegant, and totally crave-worthy.

Storage & Freezing:

Refrigerator
- Store any leftover breakfast croissant bake tightly covered or in an airtight container in the fridge for up to 4 days. For best texture, reheat slices in the oven or toaster oven to revive the flaky croissant layers, though the microwave works well for quick weekday mornings. It’s a great make-ahead breakfast you’ll actually look forward to.
Freezer
- To freeze, let the bake cool completely, then wrap individual slices tightly in plastic wrap and place them in a freezer-safe bag or container. They’ll keep well for up to 2 months. This method makes it easy to grab and go—just thaw a slice overnight in the fridge and reheat in the morning.
Reheat
- For best results, reheat in a 350°F oven for 10–15 minutes until heated through and slightly crisp on the edges. If you’re short on time, a microwave works too—heat a slice for 1–2 minutes, checking halfway through. Add a splash of milk or cover loosely with a damp paper towel if you want to keep it extra moist.

Equipment Needed:

9×13-inch baking dish
Large mixing bowl
Skillet
Whisk
Plastic wrap or foil

FAQs (People Also Ask):

Can I use store-bought croissants for breakfast casserole?
Yes, store-bought croissants work beautifully. In fact, slightly stale croissants are ideal because they absorb the egg mixture better.

How long can croissant casserole sit in the fridge before baking?
You can refrigerate the assembled casserole for up to 24 hours before baking. This flexibility makes it great for meal prep.

Can you freeze overnight croissant breakfast casserole?
Absolutely! You can freeze it unbaked or baked. Just wrap it tightly and thaw it overnight in the fridge before baking or reheating.

Why is my breakfast casserole soggy in the middle?
This usually happens if the croissants are too fresh or if the custard wasn’t fully baked. Let the casserole rest after baking to help it set.

What kind of cheese works best in breakfast casseroles?
Cheddar, mozzarella, and Swiss are all great options. Use a blend for extra flavor and texture.

Can I make this without meat?
Yes! It’s delicious with sautéed vegetables like mushrooms, spinach, and bell peppers.

External Links:

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Overnight Croissant Breakfast Casserole

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Mark Anthony

This Overnight Croissant Breakfast Casserole is buttery, savory, and perfect for stress-free mornings. Prep it the night before, then bake and enjoy! Loaded with sausage, cheese, and flaky croissants for a cozy, crowd-pleasing breakfast or brunch.

Print Recipe Pin Recipe

Prep Time 20

Cook Time 45

Chilling 8

Total Time 9 5

Course Breakfast

Servings 10

Calories 420 kcal

Ingredients

6 large butter croissants preferably day-old
1 lb breakfast sausage or bacon/ham
1 ½ cups shredded sharp cheddar cheese
1 cup shredded mozzarella cheese
8 large eggs
2 cups whole milk
½ cup heavy cream
1 tsp Dijon mustard
½ tsp garlic powder
½ tsp onion powder
Salt and pepper to taste
2 tbsp chopped chives or green onions optional, for garnish

Instructions

Brown the Sausage: In a skillet over medium heat, cook your sausage until fully browned. Drain excess fat and set aside to cool.
Tear the Croissants: Roughly tear the croissants into bite-sized chunks and layer them in a greased 9×13-inch baking dish.
Add the Sausage & Cheese: Sprinkle the cooked sausage evenly over the croissants, followed by the cheddar and mozzarella cheeses.
Make the Egg Mixture: In a large bowl, whisk together the eggs, milk, cream, Dijon, garlic powder, onion powder, salt, and pepper.
Pour the Custard: Slowly pour the egg mixture over the croissant mixture, making sure everything is evenly coated.
Cover & Chill: Cover the dish tightly with plastic wrap or foil and refrigerate overnight (at least 8 hours).
Bake in the Morning: Preheat oven to 350°F (175°C). Remove the casserole from the fridge and let it sit at room temp for 20 minutes. Bake uncovered for 45–50 minutes until golden and set in the middle.
Garnish & Serve: Let cool for 5 minutes, sprinkle with fresh chives, and serve warm.

Notes

Overnight Croissant Breakfast Casserole – Helpful Tips

✅ Cooking Tips & Techniques
• Use day-old or slightly stale croissants—they soak up the custard better without falling apart.
• Tear croissants into large chunks for a rustic look and better texture contrast once baked.
• Whisk the custard mixture thoroughly to ensure the eggs, milk, and seasonings are evenly incorporated.
• Let the casserole sit overnight (8–12 hours) in the fridge so every bite gets soaked in that savory custard.
• Bake uncovered for a golden, crisp top—tent with foil halfway through if it browns too quickly.

✅ Serving Suggestions
• Serve warm with a side of fresh fruit or citrus salad to balance the richness.
• A dollop of creamy Dijon mustard or hot sauce on the side adds zing.
• Pair with a simple arugula or mixed greens salad tossed in vinaigrette for a brunch-style plate.
• Great with freshly brewed coffee or mimosas—brunch done right!

✅ Make-Ahead & Storage
• Assemble the casserole the night before and refrigerate. Just pop it in the oven in the morning—perfect for holidays or weekend brunch.
• Leftovers keep well in the fridge for up to 4 days. Reheat individual portions in the microwave or oven.
• You can freeze the fully baked casserole (cooled and wrapped) for up to 2 months. Thaw overnight and reheat at 350°F until warmed through.

✅ Tasty Variations to Try
• Spinach & Feta – Add sautéed spinach and crumbled feta cheese for a Mediterranean twist.
• Bacon Lover’s Edition – Use cooked, crumbled bacon instead of sausage or ham.
• Southwest Style – Mix in diced green chiles, pepper jack cheese, and a dash of cumin.
• Mushroom & Swiss – Sauté mushrooms with garlic and thyme, then layer them in with shredded Swiss cheese.
• Sweet & Savory – Add a hint of maple syrup to the custard and a sprinkle of sharp cheddar for that salty-sweet combo.

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Conclusion:

There’s something so satisfying about waking up to a warm, bubbling dish of Overnight Croissant Breakfast Casserole. It’s rich, comforting, and absolutely packed with flavor—yet unbelievably easy to pull off. Whether you’re hosting brunch, feeding a hungry family, or just want to treat yourself to something special, this recipe delivers every time. The buttery croissants, savory sausage, and creamy custard hit all the right notes.

So go ahead—grab those croissants, prep it tonight, and bake it tomorrow. You’ll be starting your morning with a golden, delicious win. If you make this casserole, include me in your post—I’d love to see how yours turns out! Until then, keep cooking with joy and flavor. 🧑‍🍳