| | |

Sausage Breakfast Casserole

This post may contain affiliate links. Please read our disclosure policy.

This Sausage Breakfast Casserole is a savory, make ahead baked casserole you will love. It’s rich in flavor with toasted croissants, dreamy custard, browned sausage and onion. It’s a holiday-worthy meal for breakfast or brunch that’s as simple as it can be.

Top view of baked Sausage Breakfast Casserole with fresh herbs, scallions, and cheese in a white baking dish

Want to save this recipe?

Enter your email, and we’ll send it to your inbox. Plus, you’ll get delicious new recipes from us every Friday!

Save Recipe

A tiny bit decadent, this oh-so-simple breakfast casserole is made with toasted croissants that stand up perfectly in the custard with bits of sweet Italian sausage, fresh herbs, and delicious, gooey cheese throughout.

Perfect for holidays, like Christmas morning, or any other holiday where you’re serving brunch. Make it the night before a special meal and pop it in the oven for an hour before serving.

Foolproof and utterly delicious. And with so little prep, it’s a go-to, crowd pleasing casserole you’ll love.

What to Love About a Breakfast Casserole

When it comes to holiday mornings, especially Christmas morning, or for a special brunch, the less you have to do before the meal, the better. Here are a few reasons I love to serve this sausage breakfast casserole:

  • Make ahead friendly: assemble the casserole the night before and let it sit in the refrigerator overnight. When you’re ready to bake, simply pop it in the oven!
  • Rich in flavor that leans heavily on croissants and sausage, requiring only a handful of ingredients.
  • Extremely versatile and easy to substitute or swap ingredients for your favorites.
Top view of Sausage Breakfast Casserole ingredients on a round wood board

Sausage Breakfast Casserole Ingredients

Specific ingredient measurements are in the recipe card below, but here’s the list of what you’ll need for this breakfast casserole:

  • Croissants
  • Fresh scallions (or green onions)
  • Sweet Italian sausage, casings removed. I love the flavor of sweet Italian sausage in the morning, but use your favorite.
  • Fresh herbs: While optional, fresh herbs give this simple breakfast casserole a delightful layer of flavor. I harvested a variety of herbs still living in my herb garden that included thyme, parsley, and tarragon. Fresh sage would be delicious too.
  • Large eggs for the custard
  • Milk: I used a combination of milk and a splash of heavy cream but use your favorite milk (dairy or nondairy) and add the cream if you like for extra richness.
  • Shredded cheese like (Gruyère, Swiss, Mozzarella, or Italian shredded)
  • Salt, pepper, and olive oil for sauteing the sausage.

Breakfast Casserole Ingredient Substitutions

Can you use another bread instead of croissants?

Absolutely! I like to use a light bread, like croissants, for the best texture. But you could also use cubed or torn pieces of brioche, challah, country loaf or even soft whole wheat. I try to avoid bread that is seedy or grainy.

Is it important to toast the bread?

You can most definitely skip this step, but here’s why I do it. It’s important to use dry bread so it can absorb the delicious custard. You can use day old bread, or dry it in a low oven. But by toasting the bread in a hot oven, you develop a toasted, caramelized flavor that is so nice.

What else can you use instead of sausage?

Sweet sausage brings a delightful, breakfast flavor to this casserole. But cooked bacon and cubed ham would also be delicious!

How to Make this Sausage Breakfast Casserole

You can find step-by-step instructions in the recipe card below, but here is a quick overview on how to make this incredibly simple overnight breakfast casserole.

Toast the croissants: 

Slice the croissants in half lengthwise and toast in a hot oven for a few minutes. Let cool and tear into bite-size pieces. Set aside.

Top view of toasted, halved croissants

Brown sausage: 

Brown sausage and sliced scallions in a skillet until well browned; about 5 minutes.

Top view of browned sausage and scallions in a skillet

Assemble the casserole: 

Toss the torn croissants and sausage together and add to a lightly oiled 9×13-inch baking pan.

Top view of toasted croissants and sausage in a white baking dish

In a separate bowl, whisk together the eggs, milk, cream, shredded cheese and seasoning. Pour the egg custard over the top of the croissants and gently press them into the custard. Cover and refrigerate for 4 hours to overnight.

Top view of unbaked Sausage Breakfast Casserole in a white baking dish

Bake the Casserole: 

Bake until golden brown and firm to the touch, about 40 to 45 minutes.

Top view of baked Sausage Breakfast Casserole with fresh herbs and scallions on top

Breakfast Casserole Tips and Questions

How long can I keep a breakfast casserole in the refrigerator before cooking it?

The casserole needs at least 4 hours to overnight in the refrigerator for the croissants to absorb the liquid from the egg custard. It’s best to bake the casserole within a day.

How long will breakfast casserole leftovers keep in the fridge?

Refrigerate any leftovers within 2 hours. Wrap well as it will keep for 3 to 4 days in the refrigerator.

Can you freeze breakfast casserole leftovers?

Absolutely. I like to cut them into serving sizes, wrap individually and store in a freezer safe container. It will keep for up to 3 months. Unbaked breakfast casserole should not be frozen.

How do I tell if my breakfast casserole is done?

The USDA advises that a breakfast casserole should be baked until the center of the casserole reaches an internal temperature of 160°F.

More Recipes You May Also Enjoy


Make sure you don’t lose track of this recipe by pinning it for later! If you are not already, you can follow me on Pinterest, as well as keep up with me on FacebookInstagram, and YouTube. If you make this recipe, I would also love it if you’d tag me in your photos and leave a star rating below!

Side view of Sausage Breakfast Casserole serving on a white plate
Side view of individual serving of Sausage Breakfast Casserole on a white plate

Sausage Breakfast Casserole

This Sausage Breakfast Casserole is a savory, make-ahead baked casserole you will love. It's rich in flavor with toasted croissants, dreamy custard, browned sausage, and onion. It's a holiday-worthy meal for breakfast or brunch that's as simple as it can be.
5 from 2 votes
Print Pin Save
Prep Time: 15 minutes
Cook Time: 40 minutes
Chilling Time: 4 hours
Total Time: 4 hours 55 minutes
Servings: 12 servings
Author: Stephanie Wilson


  • 1 pound croissants about 5 to 7, split in half lengthwise
  • 1 tablespoon extra-virgin olive oil
  • 1 bunch scallions 6 to 7, white and light green parts thinly sliced, greens reserved
  • ¾ pound sweet Italian sausage casings removed
  • 2 teaspoons finely chopped herbs optional
  • 8 large eggs
  • 4 cups milk or combination of milk and heavy cream 3:1 ratio
  • 8 ounces 2 cups shredded cheese (Gruyère, Swiss, Mozzarella, Italian shredded)
  • 1 teaspoon fine sea salt or to taste
  • 1 teaspoon black pepper


  • Toast the croissants: Heat oven to 500 degrees. Spread croissants on a large baking sheet and toast, cut side up, until golden brown, 5 to 10 minutes. They brown really quickly, so keep a careful watch. Let cool slightly and tear into large, bite size pieces.
  • Brown sausage: In a skillet over medium-high heat, warm the olive oil. Then add sliced scallions and sausage meat; cook, breaking up as it cooks, until it is well browned; about 5 minutes. Remove from heat and set aside.
  • Combine ingredients: In a large bowl, toss together the croissants and sausage mixture. In a separate bowl, whisk together eggs, milk, cream, 1½ cups cheese, plus the salt and pepper.
  • Prepare casserole and chill: Lightly oil a 9- x 13-inch baking dish. Transfer the croissant mixture to the pan and spread evenly. Pour the egg custard over the top, gently pressing the croissants into the custard to help absorb the liquid. Cover and refrigerate for at least 4 hours or overnight.
  • Bake the Breakfast Casserole: Preheat the oven to 350°F and scatter the remaining cheese over the top of the casserole. Bake until golden brown and firm to the touch, about 40 to 45 minutes. Let stand for 10 minutes before serving. Garnish with reserved scallion tops.



Calories: 380kcal | Carbohydrates: 22g | Protein: 18g | Fat: 24g | Saturated Fat: 11g | Polyunsaturated Fat: 2g | Monounsaturated Fat: 9g | Trans Fat: 0.01g | Cholesterol: 171mg | Sodium: 739mg | Potassium: 314mg | Fiber: 1g | Sugar: 9g | Vitamin A: 708IU | Vitamin C: 1mg | Calcium: 293mg | Iron: 2mg

Nutritional information is only an estimate. The accuracy of the nutritional information for any recipe on this site is not guaranteed.

Tried this recipe? Pin it Today!Follow me on Pinterest for more and use the "Pin" button at the top of the recipe card.
Course: Breakfast
Cuisine: American
Keyword: breakfast casserole with sausage, croissant breakfast casserole, sausage breakfast casserole

Leave a Reply

Your email address will not be published. Required fields are marked *

Recipe Rating