Croissant Breakfast Casserole

This croissant breakfast casserole is an easy brunch recipe that looks impressive and tastes even better. Buttery croissants are baked with ham, Gruyère, Havarti, and a creamy egg custard until the center is tender and the top is golden and cheesy. It’s perfect for holiday mornings, weekend brunch, or anytime you need a comforting breakfast for a crowd.

Why I Love This Croissant Breakfast Casserole

Having a go-to breakfast recipe that can feed a crowd is essential, especially during the holiday season. I’ve been loving croissant breakfast sandwiches lately, so I wanted to turn my favorite one into an easy breakfast casserole I could make whenever I’m hosting.

That’s how this ham and cheese croissant breakfast casserole came together, and it’s exactly what I was hoping for. The croissants soak up the creamy egg custard while still keeping some of their buttery texture, and the ham, Gruyère, and Havarti make every bite rich and cheesy. It'll impress at any holiday brunch but it's still easy enough to make for a regular weekend breakfast.

Ingredients You'll Need

• 8 small croissants, torn into pieces
• 1 cup shredded ham
• 2 cups shredded Gruyère cheese
• ½ cup Havarti cheese, cut into chunks
• 8 large eggs
• 2 cups heavy cream
• Big pinch of thyme
• 2 teaspoons Dijon mustard
• 1 and ½ teaspoons granulated garlic
• 1 and ½ teaspoons kosher salt
• 1 teaspoon cracked black pepper
• Fresh chives or thyme for garnish, optional

Ingredient Notes That Make This Breakfast Casserole Better

• Croissants: day-old or slightly stale croissants actually work really well because they absorb the custard without getting as mushy.
• Ham: shredded or finely chopped ham distributes more evenly through the casserole than large slices.
• Gruyère + Havarti: Gruyère gives you the nutty, savory flavor while Havarti adds extra creaminess and melt.
• Heavy cream: this is what gives the egg mixture a rich, custardy texture. I wouldn’t swap it for a much thinner milk without noting that the casserole will be less rich.
• Dijon mustard: it won’t make the casserole taste strongly like mustard. It adds a little tang and works especially well with the ham and Gruyère.

How to Make Croissant Breakfast Casserole

Step 1: Layer The Croissants

Preheat the oven to 350°F and lightly grease a 9×13-inch baking dish. Tear the croissants into large pieces and spread them evenly in the dish. Scatter the shredded ham, Gruyère, and Havarti throughout the croissants so every portion gets plenty of filling.

Step 2: Make the Egg Custard

In a large bowl whisk together the eggs, heavy cream, Dijon mustard, granulated garlic, kosher salt, black pepper, and thyme until smooth and fully combined with no streaks of egg white remaining.

Step 3: Assemble the Casserole

Pour the egg mixture evenly over the croissants. Gently press the croissant pieces down with a spoon or spatula so they can soak up some of the custard without completely flattening them.

Step 4: Bake

Cover the baking dish with foil and bake for 30-45 minutes, or until the center is set and no longer looks wet or overly jiggly. Remove the foil and broil for 2-3 minutes, watching closely, until the top is golden brown and the cheese is bubbling.

Step 5: Rest and Serve

Let the casserole rest for about 5-10 minutes before serving so the custard has a chance to set slightly. Garnish with fresh chives or thyme if desired and serve warm.

My Tips for the Best Croissant Breakfast Casserole

• Leave some croissant edges exposed. You want most of the croissants to soak up the custard, but letting a few pieces stick up above the surface gives you those golden, slightly crispy edges on top.
• Grate the Gruyère yourself. Freshly shredded cheese melts much more smoothly than pre-shredded cheese and gives the casserole a creamier, more cohesive texture.
• Taste your ham before adding all the salt. Ham, Gruyère, and Havarti can all be fairly salty. If your ham is especially salty, slightly reduce the added salt so the finished casserole stays balanced.
• Give very fresh croissants a short soak. If your croissants are especially soft and fresh, let the assembled casserole sit for about 10-15 minutes before baking so they have time to absorb some of the custard.
• Don’t pack the croissants too tightly. Leaving a little space between the pieces allows the custard to flow around them and keeps the casserole light instead of turning into one dense layer.
• Cover the top if it browns too quickly. If the croissants are getting dark before the center is fully set, loosely tent the casserole with foil and let it continue baking until the custard is cooked through.

Croissant Breakfast Casserole Make Ahead Instructions

This croissant breakfast casserole is perfect for making ahead, which is one of my favorite things about it for holiday mornings and weekend brunches. You can do all the prep the night before, then just bake it in the morning.

Assemble the night before: Prepare the casserole through pouring the egg custard over the croissants and gently pressing them down. Cover the baking dish tightly and refrigerate overnight. As it sits, the croissants have plenty of time to soak up the creamy custard.

Bake in the morning: Take the casserole out of the refrigerator about 30 minutes before baking. Remove the plastic wrap, cover with foil, and bake as directed. Since the casserole is starting cold, it may need an extra 5-10 minutes in the oven. Bake until the center is completely set and no longer looks wet.

If you have leftovers: Store the casserole covered or in an airtight container in the refrigerator for up to 3-4 days. To reheat, cover the baking dish with foil and warm in a the oven at 325°F for a few minutes.

Croissant Breakfast Casserole FAQs

Do I need to use day-old croissants?

No, fresh croissants will work, but slightly stale croissants are actually great for this casserole because they absorb the egg custard without becoming overly soft. If your croissants are very fresh, letting the assembled casserole sit for 10-15 minutes before baking helps them soak up more of the custard.

Do I have to soak croissant breakfast casserole overnight?

No. This recipe can be assembled and baked the same day, so there’s no overnight soak required. If you want to prepare it ahead for a holiday or brunch, you can also assemble it the night before and refrigerate it until you’re ready to bake.

Can I use bacon or sausage instead of ham?

Yes. Cooked bacon or breakfast sausage can replace the ham, or you can use a combination of meats. Just make sure sausage is fully cooked and excess grease is drained before adding it to the casserole.

What cheese works best in a croissant breakfast casserole?

I use Gruyère and Havarti because Gruyère adds a savory, nutty flavor while Havarti melts especially creamy. Swiss, cheddar, fontina, Monterey Jack, or a combination of your favorite melting cheeses can also work.

Can I use milk instead of heavy cream?

Yes, but the casserole won’t be quite as rich or custardy. Whole milk or half-and-half would be the best substitutes. I wouldn’t recommend using a very low-fat milk if you want the same creamy texture.

Why is my croissant breakfast casserole soggy?

A soggy casserole usually means the center needs more baking time or the croissants absorbed more custard than expected. Bake until the center is completely set and no longer looks wet. Very fresh croissants may also create a softer texture than slightly stale ones.

How do I know when croissant breakfast casserole is done?

The casserole is done when the egg custard is set in the center and no longer looks wet or excessively jiggly. The croissants should be golden on top and the cheese should be completely melted and bubbling.

What size baking dish should I use?

A 9×13-inch baking dish works well for this recipe. Using a significantly smaller dish will make the casserole deeper and may increase the baking time, while a larger dish can make it cook more quickly.

More Breakfast Casserole Recipes to Try

• Sausage casserole
• Challah French toast casserole
• Bisquick breakfast casserole
• Christmas breakfast casserole
• Jimmy Dean breakfast casserole