Croissant Breakfast Casserole Recipe | Buttery, Cheesy, and Perfect for Brunch

Flaky, buttery croissants layered with melty cheese, fluffy eggs, and savory add-ins like sausage or veggies—Croissant Breakfast Casserole is the brunch dish you didn’t know you needed. It’s rich, comforting, and incredibly easy to prep. You can assemble it the night before and pop it in the oven the next morning. Whether you’re feeding a crowd or just treating yourself, this casserole hits all the right notes.

Why You’ll Love This Casserole

This isn’t your average breakfast bake. It’s extra rich, extra flaky, and ultra satisfying.

Here’s why it’s a winner:

• Uses buttery croissants instead of plain bread
• Easy to customize with proteins, cheese, or veggies
• Can be made ahead for zero stress in the morning
• Feels fancy but takes minimal effort
• One dish feeds a whole group

It’s brunch magic with bakery-level flavor and no early morning fuss.

What You’ll Need

Simple ingredients, maximum flavor.

Base Ingredients

• 5–6 large croissants (day-old is best)
• 6 large eggs
• 1½ cups milk (whole, oat, or plant-based)
• ½ cup heavy cream (or more milk)
• 1 teaspoon Dijon mustard
• Salt and black pepper to taste

Fillings (Customizable)

• 1 cup shredded cheese (cheddar, Swiss, mozzarella, etc.)
• 1 cup cooked breakfast sausage, bacon, or chopped ham
• ½ cup sautéed onions, spinach, or bell peppers
• Optional: fresh herbs like chives or parsley

You can mix and match to make it your own!

How to Make Croissant Breakfast Casserole

This recipe is all about layering and baking—super simple.

Step 1: Prep the Croissants

• Cut croissants into bite-sized pieces
• Place in a greased 9×13-inch baking dish
• Lightly toast them in a 300°F oven for 5–10 minutes if they’re very fresh (optional)

Day-old croissants are best—they soak up the custard without turning soggy.

Step 2: Add the Fillings

• Sprinkle cheese, cooked meat, and veggies over the croissants
• Make sure everything is evenly distributed

This ensures every bite has that savory, cheesy magic.

Step 3: Make the Egg Mixture

• In a bowl, whisk together eggs, milk, cream, Dijon, salt, and pepper
• Pour the mixture evenly over the croissants and fillings

Press down gently so the croissants soak up the egg mixture.

Step 4: Rest or Bake

• Option 1: Cover and refrigerate overnight
• Option 2: Let it sit for 20–30 minutes before baking

Both options work—just let the custard settle in.

Step 5: Bake

• Preheat oven to 350°F (175°C)
• Bake uncovered for 40–50 minutes, until puffed and golden
• Center should be set, and a knife should come out clean

Let it rest for 5–10 minutes before slicing and serving.

Tips for the Best Breakfast Casserole

Want your casserole golden, fluffy, and full of flavor? Follow these tips:

• Use day-old croissants for better texture
• Don’t skip the Dijon—it adds subtle tang and depth
• Use whole milk or cream for richness
• Let it sit overnight if possible—the flavor deepens
• Add a sprinkle of cheese on top for a golden finish

Bonus: If you’re using salty meats like bacon, reduce added salt a bit.

Flavor Variations You’ll Love

This recipe is super customizable—make it your own every time.

Meaty Versions

• Sausage + cheddar + chives
• Ham + Swiss + spinach
• Bacon + mozzarella + mushrooms

Vegetarian Options

• Spinach + sun-dried tomatoes + feta
• Bell peppers + onions + cheddar
• Zucchini + herbs + goat cheese

Sweet Spin

• Croissants + cinnamon + berries + maple custard
• Swap Dijon for vanilla and reduce salt for a sweet twist

You can take this basic structure in any direction.

What to Serve With It

This casserole is rich—balance it with fresh or light sides.

Perfect Pairings

• Fresh fruit salad
• Green salad with vinaigrette
• Crispy hash browns or roasted potatoes
• Coffee, mimosas, or fresh juice

It’s the main event, so you don’t need much else on the table.

Make-Ahead & Storage Tips

This casserole was made for stress-free mornings.

To Make Ahead

• Assemble the casserole the night before
• Cover tightly and refrigerate overnight
• Bake in the morning as directed

You can also bake it fully, then reheat slices as needed.

Storing Leftovers

• Store in an airtight container in the fridge for up to 4 days
• Reheat in the oven or microwave until warmed through

Freezing

• Freeze fully baked casserole slices for up to 2 months
• Thaw in the fridge overnight and reheat at 350°F until hot

Leftovers = weekday breakfast gold.

Print

FAQs

1. Can I use fresh croissants?

You can, but day-old croissants work better. Fresh ones are very soft and can get soggy. If you’re using fresh, try lightly toasting the pieces in the oven for a few minutes before layering. This helps them hold up better to the custard mixture.

2. Can I make this casserole vegetarian?

Absolutely. Just skip the meat and load it up with veggies like sautéed spinach, mushrooms, onions, or bell peppers. Add a flavorful cheese like feta or goat cheese to boost richness. It’s just as satisfying, and you won’t miss the meat.

3. What’s the best cheese to use?

Cheddar, Swiss, mozzarella, and Gruyère are all great. For extra flavor, try a mix—like sharp cheddar and Monterey Jack. If you’re doing a French twist, use Brie or a little bit of blue cheese. Choose a cheese that melts well and complements your fillings.

4. Can I prep this more than one day in advance?

Yes! You can assemble it up to 2 days in advance, tightly cover it, and keep it in the fridge. Just be sure it’s covered well to prevent drying out. When you’re ready to bake, let it sit at room temp for 15–20 minutes before popping it in the oven.

5. How do I prevent the casserole from being too soggy?

Use day-old croissants and don’t add too much liquid. Make sure to bake it uncovered so the top crisps up. If using juicy vegetables (like tomatoes or mushrooms), sauté them first to remove excess moisture. Letting it sit before slicing also helps it set.

6. Can I make a smaller batch?

Yes! Halve the ingredients and bake in an 8×8-inch dish. The bake time will be slightly shorter—start checking at around 30–35 minutes. Perfect for smaller households or cozy breakfasts for two.

7. Can I add eggs directly on top for a fancier look?

You can! After baking halfway, carefully crack eggs over the top and return to the oven. Bake until the whites are set but yolks are still runny. It’s a great way to level up the presentation and add extra richness.

8. Can I make this dairy-free?

Yep. Use plant-based milk (like almond or oat) and a non-dairy cream (like coconut cream or oat-based heavy cream). Use vegan cheese or nutritional yeast for cheesy flavor. It’s just as rich and flavorful with the right swaps.

9. Can I use crescent rolls or regular bread instead of croissants?

Yes! Crescent rolls give a similar buttery vibe. You can also use cubed brioche, sourdough, or sandwich bread. Just make sure whatever bread you use is slightly stale or toasted for best texture.

10. Is this casserole freezer-friendly?

Totally. Bake the casserole, cool it completely, then freeze in slices. Wrap tightly or store in freezer containers for up to 2 months. Thaw in the fridge overnight and reheat at 350°F for 15–20 minutes until hot and bubbly.