Flaky on top, custardy in the middle, cheesy all the way through — and you can throw the whole thing together the night before. This is the brunch recipe that makes everyone quiet at the table, in the best possible way.
Okay, so I made this on a Sunday morning when I had leftover croissants sitting on the counter and zero motivation to do anything complicated. I wasn’t expecting much — honestly, I just didn’t want them to go to waste. But when this came out of the oven? Flaky on top, custardy in the middle, cheesy all the way through… yeah. It immediately became a permanent part of my brunch rotation.
This croissant breakfast casserole is the kind of dish that makes people think you spent your whole morning in the kitchen. You didn’t. You can actually throw it together the night before, let it sit in the fridge, and just slide it into the oven when you wake up. That alone makes it one of my favorite easy brunch recipes for holidays, weekends, or honestly any time I have people over.
It’s got sausage, eggs, melty cheese, and buttery croissants soaked in a rich, creamy egg custard. Every bite feels warm and indulgent without being over the top. It’s the kind of food that makes everyone quiet at the table — in a good way.
If you’ve been looking for a make-ahead breakfast that works for a crowd without stressing you out, this is it. Trust me on this one.
Why You’ll Love This Recipe
- No complicated steps — just layer, pour, bake. Done.
- Make it the night before — perfect for holiday mornings or lazy weekends
- Feeds a crowd — fills a 9×13 pan easily, great for 8–10 people
- Incredibly satisfying — creamy egg bake meets flaky croissant = perfect combo
- Customizable — swap the sausage, change up the cheese, add veggies
- Kid-approved — my family demolished this in under 20 minutes
Step-by-Step Instructions
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1Cook the sausage. In a large skillet over medium heat, cook the breakfast sausage, breaking it up as it cooks. Drain any excess fat and set aside to cool slightly.
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2Prep your baking dish. Lightly grease a 9×13 baking dish with butter or cooking spray.
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3Layer the croissants. Tear or cut your croissants into roughly 2-inch chunks and spread them evenly in the baking dish. Don’t press them down — you want them a little airy so they soak up the custard nicely.
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4Add the sausage and cheese. Scatter the cooked sausage evenly over the croissant pieces. Sprinkle 1 cup of the cheddar and all of the mozzarella over the top.
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5Make the egg custard. In a large bowl, whisk together the eggs, milk, heavy cream, garlic powder, onion powder, salt, pepper, and Dijon mustard (if using) until smooth and well combined.
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6Pour and press. Pour the egg mixture evenly over the casserole. Gently press the croissants down with a spatula so they start to absorb the custard. Sprinkle the remaining ½ cup of cheddar on top.💡 Really press those croissants down so they’re partially submerged — this creates the signature custardy interior instead of dry patches.
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7Rest (overnight or 30 minutes minimum). Cover with plastic wrap and refrigerate overnight, or let sit at room temperature for at least 30 minutes before baking. The longer it soaks, the better.⚠️ Don’t skip this step — soaking time is what transforms this from a simple bake into something genuinely custardy and special. Overnight is ideal.
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8Bake. Preheat your oven to 350°F (175°C). Remove the casserole from the fridge and let it sit at room temperature for 15 minutes while the oven heats. Bake uncovered for 45–50 minutes, until the top is golden and the center is set. A knife inserted in the center should come out clean.💡 If your oven runs hot, tent with foil for the first 25 minutes then uncover to let the top brown — this prevents the cheese from over-crisping before the center sets.
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9Rest and serve. Let it cool for 5–10 minutes before slicing. Garnish with fresh chives or parsley if you want it to look extra beautiful.
Croissant Breakfast Casserole (The Brunch Everyone Will Ask You to Make Again)
🧄 Ingredients
- 6 ¾ large croissants (day-old, torn into chunks)
- 1 ¾ lb breakfast sausage
- 8 ¾ large eggs
- 2 ¾ cup whole milk
- 0.5 cup heavy cream
- 1.5 cup shredded cheddar cheese (divided)
- 0.5 cup shredded mozzarella cheese
- 1 ¾ tsp garlic powder
- 0.5 tsp onion powder
- 0.5 tsp black pepper
- 0.5 tsp salt
- 1 ¾ tsp Dijon mustard
- 2 ¾ tbsp fresh chives or parsley
📋 Instructions
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1
In a large skillet over medium heat, cook the breakfast sausage, breaking it up as it cooks. Cook until no longer pink, about 7–8 minutes. Drain any excess fat and set aside to cool slightly.
💡 Don\'t overcook — the sausage will continue cooking in the oven. -
2
Lightly grease a 9x13 inch baking dish with butter or non-stick cooking spray.
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3
Tear or cut the croissants into roughly 2-inch chunks and spread them evenly in the prepared baking dish. Don\'t press them down.
💡 Leaving them airy helps them soak up the custard evenly. -
4
Scatter the cooked sausage evenly over the croissant pieces. Sprinkle 1 cup of cheddar cheese and all of the mozzarella over the top.
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5
In a large bowl, whisk together the eggs, whole milk, heavy cream, garlic powder, onion powder, salt, black pepper, and Dijon mustard until smooth and fully combined.
💡 Taste and adjust seasoning before pouring — every sausage brand is different in saltiness. -
6
Pour the egg mixture slowly and evenly over the casserole. Gently press the croissants down with a spatula so they begin to absorb the custard. Sprinkle the remaining ½ cup of cheddar cheese on top.
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7
Cover with plastic wrap and refrigerate overnight, or let rest at room temperature for at least 30 minutes before baking.
💡 Overnight soaking gives the best custardy texture. -
8
Preheat your oven to 350°F (175°C). Remove the casserole from the fridge and let it sit at room temperature for 15 minutes while the oven heats. Bake uncovered for 45–50 minutes, until the top is golden and the center is set.
💡 If the top browns too quickly, tent loosely with foil for the last 15 minutes. -
9
Remove from the oven and let cool for 5–10 minutes before slicing. Garnish with fresh chives or parsley and serve warm.
💡 Resting helps the casserole set up for cleaner slices.
Nutrition Per Serving
💡 Pro Tips
- Day-old croissants are ideal. Fresh croissants can get a bit mushy because they’re already soft. Slightly stale ones hold up better and soak up the custard without falling apart.
- Don’t skip the rest time. Even 30 minutes makes a difference. Overnight is the move if you can swing it.
- Cover with foil for the first 25 minutes if your oven runs hot — then uncover to let the top brown. This prevents the cheese from over-crisping before the center sets.
- Press the croissants down after pouring the custard. This helps them absorb evenly and creates that perfect custardy interior.
- Let it rest before cutting. I know, it’s hard to wait, but 5–10 minutes means cleaner slices and a better texture.
- Season to taste — taste your egg mixture before pouring. Every sausage brand is different in saltiness, so adjust accordingly.
Variations to Try
Swap regular breakfast sausage for spicy Italian sausage or add ½ tsp crushed red pepper flakes to the egg custard. Top with a drizzle of hot sauce before serving.
Skip the meat entirely and sauté diced bell peppers, mushrooms, baby spinach, and onions in a little olive oil. Use them in place of the sausage. Just as satisfying, honestly.
Replace sausage with 8 strips of cooked, crumbled bacon and swap cheddar for Swiss cheese. Add a pinch of nutmeg to the custard — it gives it a slightly fancy, savory croissant strata vibe.
No time to soak overnight? Assemble the casserole, press everything down firmly, and bake after just 20–30 minutes of soaking. The texture will be slightly lighter but still delicious.
Serving Ideas
- Serve alongside a simple green salad or fresh fruit for a complete brunch spread
- Pair with a hot cup of coffee, fresh OJ, or a light mimosa
- Add a dollop of sour cream or hot sauce on the side for those who like a little kick
- Works great as a holiday brunch centerpiece — put it in the middle of the table and let people dig in family-style
- Leftovers make an incredible next-day lunch — just reheat a square and you’re set
Storage & Reheating
| Where | How long | Notes |
|---|---|---|
| ❄️ Fridge | Up to 4 days | Tightly covered in the baking dish or transferred to an airtight container |
| 🧊 Freezer | Up to 2 months | Cool completely, slice into portions, wrap individually — thaw overnight in the fridge before reheating |
| 🔥 Microwave | 60–90 seconds | Individual slices — quick and easy for leftovers |
| 🔥 Oven reheat | 15–20 min at 325°F | Cover with foil to prevent drying out — best for larger portions |
Frequently Asked Questions
If you make this croissant breakfast casserole, I really think it’s going to become one of those recipes you come back to again and again. It’s one of those dishes that just works — for holidays, lazy Sundays, potlucks, or whenever you need something that feels a little special without a lot of effort.
I’d love to know how yours turns out! Drop a comment below, and if you share it on Pinterest or Instagram, tag me so I can see your beautiful brunch spread. 🥐 Happy cooking, friends.
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