Name: Sausage Croissant Breakfast Casserole with Bacon and Gouda
Prep time: 30 min
Cook time: 65 min
Total time: 215 min
Ingredients: 18 ounces grocery store croissants (, day old (about 7 to 8 large croissants, see Note 1)); 6 large eggs; 1 cup whole milk ((see Note 2)); 1 cup heavy cream ((see Note 2)); 1 tablespoon Dijon mustard ((I use Maille)); ½ to ¾ teaspoon Diamond Crystal kosher salt ((depending on the saltiness of your bacon and sausage)); ½ teaspoon freshly ground black pepper; ½ teaspoon sweet paprika ((I use Hungarian)); ½ teaspoon onion powder; ¼ teaspoon garlic powder; 10 ounces loose pork breakfast sausage ((see Note 4)); 6 ounces regular-cut bacon ((about 6 slices), diced); ½ cup chopped yellow onion; 2 large garlic cloves (, minced (about 2 teaspoons)); 6 ounces shredded Gouda ((see Note 5))

This Bacon and Sausage Croissant Breakfast Casserole is a great choice when you’re cooking for a group. Flaky croissants soak up a creamy custard, while sausage, sausage, and Gouda add plenty of savory flavor. It’s easy enough for weekends and impressive for holidays and brunch gatherings.

Golden brown croissant pieces baked into a savory sausage breakfast casserole, nestled in a creamy, cheesy egg custard with visible bits of browned sausage, bacon, and crisped edges along the baking dish.

Before You Start Cooking

Croissants. Grocery-store croissants that are a day or two old work best for soaking up the custard mixture, rather than fresh, flaky bakery croissants. Cut or tear them into uneven chunks so the custard, meats, and cheese have more places to settle in.
Sausage. I use bulk pork sausage, like Jimmy Dean, but this recipe is flexible. Any breakfast-style sausage you enjoy will work, including poultry sausage. If you’re using links, just remove the casings before cooking.
Cheese swaps. You can use any melting cheese instead of Gouda. Shredded Cheddar, Gruyère, or Monterey Jack are all good options. For the best texture, buy blocks and shred them yourself.
Pan. You’ll need a 13×9-inch baking dish, lightly greased with cooking spray.

How to Make This Sausage Croissant Breakfast Casserole

Overhead view of labeled ingredients for a savory breakfast casserole, including croissants, shredded Gouda, breakfast sausage, bacon, onion, garlic, Dijon mustard, eggs, heavy cream, whole milk, and seasonings, all arranged on a light marble surface.

Step 1: Mix the Custard

To make the custard that will bind the Sausage Croissant Breakfast Casserole, whisk together the following in a large bowl:

Eggs. Use large, whole eggs.
Dairy. A combination of whole milk and heavy cream adds richness without being too heavy. If you prefer, you can also use half-and-half.
Dijon mustard. This won’t make the casserole taste mustardy—Dijon adds a subtle savory depth and touch of acidity that balances the richer flavors of the meats and cheese.
Seasonings. Kosher salt, freshly-ground black pepper, onion powder, garlic powder, and a touch of sweet paprika.

A glass mixing bowl filled with a creamy, speckled egg custard mixture being whisked with a metal balloon whisk, prepared for a sausage croissant breakfast casserole.

Set the custard aside while you cook the meats. This gives the dried seasonings a little time to hydrate so they blend in more smoothly.

If you’re not moving right into the next steps, just cover the bowl and pop it in the fridge until you’re ready to assemble the casserole.

Step 2: Cook the Sausage, Bacon, and Onions

Start by browning the sausage in a large skillet over medium-high heat. I like to add the sausage to a cold pan. As the skillet heats, the fat in the sausage will start to render, preventing sticking without adding extra oil.

As it cooks, break the sausage into small, even crumbles with a wooden spoon. Once it’s cooked through and starting to brown, use a slotted spoon to transfer it to a paper towel-lined plate to drain off the excess grease.

Overhead view of a white enamel skillet filled with crumbled, browned breakfast sausage, freshly cooked and still steaming, on a light marble surface.

In the same skillet (no need to wipe it out), add the diced bacon (we like hickory- or applewood-smoked). Cook the bacon just until it renders its fat and begins to brown, but before it’s totally crisped. It will finish crisping in the oven as the casserole bakes.

Like the sausage, remove the bacon with a slotted spoon and drain it on a plate lined with paper towels. Carefully pour off most of the grease from the skillet into a heatproof container, leaving about a tablespoon behind.

Close-up of chopped bacon sizzling and bubbling in rendered fat in a white enameled skillet with a golden brown fond on the bottom.

Lower the heat to medium and cook the chopped yellow onions in the bacon grease until softened. Then, stir in the minced garlic (I like to use a garlic press) and cook the mixture for another 30 seconds or so, just until it’s fragrant.

Diced onion and minced garlic cooking in bacon drippings in a white skillet, surrounded by browned bits for added flavor.

Step 3: Assemble the Casserole

Scatter the croissant pieces into your prepared baking dish. Don’t worry about layering them uniformly for this recipe—a more rustic assembly is fine.

Overhead view of a baking dish filled with torn croissants next to two bowls—one with shredded cheese, and the other with a cooked mixture of sausage, bacon, and onions—showing the components for assembling a breakfast casserole.

Stir together the cooked sausage, bacon, onion, and garlic, and then spoon the mixture over and between the croissant pieces. Let some of the mixture settle toward the bottom of the pan, leaving some on top of the croissants.

Nestle the shredded Gouda between the croissant pieces. You want pockets of melted cheese throughout the baked casserole, not just on the surface.

A white rectangular baking dish filled with torn croissants, cooked sausage, crispy bacon, and shredded cheese, layered together before adding the egg mixture for a breakfast casserole.

Give the custard a final gentle whisk, and pour it evenly over the assembled casserole, letting it soak into the croissant pieces. I like to gently press down on the croissant pieces to help them absorb the custard.

Cover the baking dish with plastic wrap or foil and refrigerate it for at least 2 hours, or up to 4 hours, to allow the custard to absorb into the croissants.

I like to take the pan out of the refrigerator about 30 minutes before baking to take the chill off for the most even bake.

Step 4: Bake Until Golden

I bake this casserole in two stages: first, loosely covered with foil for 30 minutes, and then uncovered for another 15 to 20 minutes, so the exposed tops of the croissants can crisp and regain their flaky texture.

The casserole is ready when the custard is set, and the casserole is puffed, golden, and lightly crisp on the top.

Close-up of a golden-brown baked sausage croissant breakfast casserole in a white dish, showing flaky croissant layers, melted cheese, and crisp bits of bacon and sausage nestled in the custard.

Serving Sausage Croissant Breakfast Casserole

Let the casserole rest for 5 to 10 minutes before slicing. This helps it hold together and makes serving much easier.

This casserole is rich and filling, so you can cut it into 8 to 12 portions, depending on appetites and what else you’re serving. It pairs well with something fresh on the side on a breakfast or brunch buffet, like a simple fruit salad.

You can either cut this casserole into rectangles or scoop it out with a spoon for more rustic-looking servings.

Golden-brown croissant breakfast casserole in a white baking dish with a spoonful missing, showing a flaky, cheesy interior with bacon and sausage. A plated serving sits above the dish next to a bowl of whole eggs.

Make Ahead Tips

I don’t recommend fully assembling this casserole the night before and baking it in the morning. In my testing, the croissants—especially lighter, airier ones—start to break down as they sit in the custard and can turn too soft.

For the best texture, I don’t like soaking them for more than 4 hours.

That said, you can absolutely prep the components the day before you bake the casserole to make assembly easier when entertaining.

Cook the sausage mixture: Brown the sausage, bacon, onion, and garlic, then store it in an airtight container in the refrigerator. I like to microwave it for 10–15 seconds before assembling, just to take the chill off.
Mix the custard: Whisk the custard together and refrigerate it in a covered container. Give it a quick re-whisk before pouring it over the casserole.

Close-up of a slice of sausage croissant breakfast casserole showing soft, custardy layers with croissants, sausage, and melted cheese.

Storage and Reheating

Store leftover Sausage Croissant Breakfast Casserole in an airtight container in the refrigerator for up to 3 days.

You can reheat it in the microwave for convenience, but using the oven will bring back some of the crisp texture on top.

Microwave: Cut into portions and place on a microwave-safe plate. Cover with a vented lid and heat at 80% power in 20–30 second intervals until warmed through. (Timing will vary depending on your microwave and portion size.)
Oven (recommended): Place portions on a foil-lined baking sheet and cover loosely with foil. Warm in a 325°F oven for 25–30 minutes, until heated through. Remove the foil for the last 5 minutes to help re-crisp the top.