Overnight Croissant Recipe

There’s something magical about a dish that does the heavy lifting overnight. This Overnight Croissant Casserole is a true lifesaver, especially when you’re hosting a brunch or just want to enjoy a lazy weekend breakfast without the early-morning fuss. It’s got everything you want: buttery croissants, savory turkey sausage, cheesy goodness, and a hint of spices—all coming together in the perfect cozy casserole. Plus, there’s gravy (because why not?) that ties the whole thing together.

I love making this for family gatherings, particularly when I have houseguests staying over. The smell of the casserole baking in the morning is enough to get everyone out of bed with smiles on their faces!

this RECIPE

A little personal brunch story 🍽️

I first tried this overnight croissant bake when I was visiting an old friend during the holidays. She’s one of those effortlessly cool hosts who always seems to have a delicious homemade breakfast on the table, no matter how early I wake up. When I asked how she managed to pull off such a wonderful meal so early, she let me in on her secret: this casserole, prepped the night before and baked the next morning.

The next weekend, I decided to give it a try myself. I didn’t have a lot of time to spend in the kitchen, but I wanted something impressive. And let me tell you, this recipe did not disappoint. My family devoured it, and it’s been a staple in my brunch rotation ever since. The smell of those croissants, sausage, and cheese mingling in the oven still makes me think of that holiday morning.

Where this dish comes from: the evolution of breakfast casseroles

Breakfast casseroles have been around for ages. Originally, they were a way to repurpose leftovers—bread, meat, and vegetables—into a hearty, filling meal. Over time, they’ve become more refined, with countless variations popping up depending on the ingredients and flavors people love. This version gets its richness from croissants instead of regular bread, giving it a flaky, buttery texture that elevates it from the typical casserole. Pair that with savory turkey sausage, and you’ve got a meal that’s satisfying without being too heavy. And let’s not forget the gravy! A throwback to traditional Southern-style breakfast gravy, but with a bit more finesse.

Let’s talk ingredients: croissants, cheese, and the essentials

• Butter croissants: Croissants are the heart and soul of this dish. Their buttery, flaky texture soaks up the egg mixture perfectly, but still holds some structure after baking. If you’re out of croissants, you can substitute brioche or any sturdy, buttery bread (though croissants give the best results).
• Turkey sausage: Using mild turkey sausage keeps the dish light and flavorful. If you prefer a bit more heat, you can swap in a spicy turkey sausage. I’ve even tried chicken sausage, and it works just as well. Just make sure you crumble and brown it thoroughly to lock in all the flavor.
• Shredded cheddar cheese: This gives the casserole its cheesy, comforting goodness. I like to use sharp cheddar for an extra punch of flavor, but feel free to swap in your favorite cheese—Gouda or Monterey Jack are also excellent choices.
• Eggs, cream, and milk: The backbone of the custard that holds everything together. Whole milk is ideal here, but if you’re in a pinch, 2% works. The heavy cream adds richness, though you could use half-and-half if that’s what you have.
• Spices: Mustard powder, paprika, garlic powder, salt, and pepper bring just the right amount of seasoning to balance out the richness of the dish. You can adjust these based on your taste preferences—I sometimes like to add a pinch of smoked paprika for a little extra depth.

The kitchen gear you need (and what you can totally skip)

For this dish, you don’t need any fancy equipment. But having the right tools definitely makes things easier:

• Large skillet: You’ll need this to brown the turkey sausage and sauté the onions. A non-stick skillet will make cleanup easier, but any large skillet will work just fine.
• 9×13-inch baking dish: This is a must for assembling the casserole. Glass or ceramic works best, as it helps the casserole cook evenly. If you don’t have this size, you can split the mixture into two smaller dishes.
• Whisk: You’ll need it for whisking the eggs and for making the gravy. A balloon whisk is ideal, but a fork will do in a pinch.
• Plastic wrap: Essential for letting the casserole sit overnight. It keeps everything fresh while the flavors meld together.

Step-by-step: how to make this casserole (and avoid common mistakes)

1. Cook the sausage and onions: In your large skillet, heat the olive oil over medium heat. Once it’s warm, add the onions and sauté until they’re soft and translucent—about 5 minutes. Then, crumble the turkey sausage into the pan and cook until it’s completely browned. Be sure to drain the fat and save it for the gravy! (I learned the hard way that skipping this step makes the gravy a little lackluster).
2. Assemble the casserole: Tear your croissants into bite-sized pieces and mix them with the sausage, onions, and shredded cheddar cheese. Spread this mixture evenly in a greased 9×13-inch baking dish.
3. Whisk the egg mixture: In a medium bowl, whisk together the eggs, heavy cream, ½ cup of milk, mustard powder, salt, pepper, paprika, and garlic powder. Pour this over the croissant mixture in the dish. Make sure everything is well-coated. Cover with plastic wrap and refrigerate overnight (or for at least 8 hours). Trust me, this waiting period makes all the difference—it lets the croissants absorb the egg mixture.
4. Bake it: The next morning, preheat your oven to 350°F. Remove the casserole from the fridge and bake for 35-45 minutes until it’s golden brown on top and set in the middle.
5. Make the gravy: While the casserole is baking, melt butter and 1 tablespoon of the reserved sausage fat in a skillet over medium heat. Whisk in the flour and cook for about 1 minute. Slowly whisk in the remaining 2½ cups of milk, stirring constantly to avoid lumps. Let the gravy simmer for 2-3 minutes until thickened. Season with salt and pepper to taste.
6. Serve: Once your casserole is done, slice it up and serve with the gravy on the side or poured over each portion.

Mix it up: variations you’ll love

I love experimenting with this recipe, and I’ve found some fun variations to keep things interesting:

• Veggie version: Swap out the turkey sausage for sautéed mushrooms, spinach, and bell peppers. It’s just as filling and delicious, and great for vegetarians!
• Dairy-free: Substitute the milk and heavy cream with almond milk or oat milk. Just make sure they’re unsweetened! You can also use a dairy-free cheese alternative.
• Gluten-free: Use gluten-free croissants (yes, they exist!) and gluten-free flour for the gravy. I’ve tried this, and it holds up surprisingly well!
• Spicy twist: Add some diced jalapeños or red pepper flakes for a little heat. This pairs well with the mild turkey sausage.
• Seasonal flair: In the fall, I love adding a dash of nutmeg and swapping the cheddar for Gruyère cheese. It adds a warm, nutty flavor that’s perfect for cooler mornings.

How to serve (and impress your guests!)

When it comes to serving this casserole, I like to go all out. Slice it into squares and serve it family-style with the gravy in a little pitcher on the side. For garnish, I sprinkle a few chopped green onions or parsley on top—it adds a fresh pop of color and flavor.

This casserole pairs beautifully with a fresh fruit salad on the side. The sweetness of the fruit cuts through the richness of the dish and makes the whole meal feel balanced.

Ideal drinks to enjoy with your meal

This dish is perfect with a tall glass of freshly squeezed orange juice. The acidity of the juice cuts through the richness of the casserole and gravy. If you’re feeling fancy, try a sparkling water with a splash of cranberry or pomegranate juice—it adds a bit of tartness that works really well with the savory flavors. For something warm, a spiced chai latte or classic black coffee will round out your breakfast spread perfectly.

Storing and reheating tips

If you have leftovers (and that’s a big if), they store well in the fridge for up to 3 days. Just make sure you cover the casserole tightly with foil or transfer it to an airtight container. When you’re ready to reheat, pop a slice in the microwave for about a minute or reheat in the oven at 300°F for 10-15 minutes to maintain the crispiness.

As for the gravy, store it separately in an airtight container in the fridge. When reheating, add a splash of milk to loosen it up, and heat it over low heat until warm.

Scaling the recipe up or down

This recipe is easy to adjust for a crowd. If you need to make a larger batch, simply double the ingredients and use two baking dishes. Just make sure they both fit in the oven!

For a smaller crowd, halve the ingredients and bake in an 8×8-inch dish. I’ve done this when cooking for just two people, and it works perfectly. The only thing to watch out for is adjusting the baking time—smaller casseroles will bake a bit quicker.

Potential issues (and how to avoid them!)

• Soggy croissants: If your croissants are too soft after baking, it’s likely they didn’t absorb enough of the egg mixture. Make sure to let the casserole sit in the fridge for the full 8 hours to avoid this.
• Gravy too thick: If your gravy turns out too thick, just add a little extra milk, a tablespoon at a time, until you reach your desired consistency.
• Casserole undercooked: If the center of your casserole is still jiggly after baking, give it an extra 5-10 minutes in the oven. Cover the top with foil if it’s browning too much.

Give it a try—your taste buds will thank you!

This Overnight Croissant Casserole is perfect for anyone who wants to wake up to a breakfast that’s ready to pop in the oven with minimal effort. It’s versatile, flavorful, and oh-so-comforting. Whether you’re feeding a crowd or just treating yourself, this dish is sure to become a favorite in your home.

Frequently Asked Questions

Q: Can I make this casserole ahead of time?
A: Absolutely! The beauty of this recipe is that it’s designed to be made the night before. Just assemble, refrigerate, and bake in the morning.

Q: Can I freeze this casserole?
A: Yes! You can freeze the casserole before baking. Just cover it tightly and freeze for up to a month. Thaw it overnight in the fridge before baking.

Q: What can I use instead of croissants?
A: Brioche or any sturdy bread like challah would work well if you don’t have croissants on hand.

Q: Can I make this without dairy?
A: Yes, you can substitute the milk and cream with dairy-free alternatives like almond or oat milk. Just be sure to use unsweetened versions.

Q: How long does this casserole last?
A: It’ll keep in the fridge for up to 3 days. Just reheat individual portions in the microwave or oven when you’re ready to eat.

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