This is the breakfast I make when we have a house full of guests and I want a dish that basically makes itself. My easy Breakfast Casserole with Sausage is a cozy and perfect dish to serve a hungry breakfast crowd. My personal chef clients loved this dish because they could just heat it up in the morning for a quick and hearty breakfast. It comes together with a little sauteing and whisking and is endlessly adaptable. Swap in whatever meats, vegetables and cheeses you have on hand.

A quick look at My Breakfast Casserole recipe

Recipe Name: Breakfast Casserole with Sausage
Ready In: 15 minutes prep, 45 minutes cook time
Serves: 8
Calories: 364 per serving
Main Ingredients: Eggs, breakfast sausage, cheddar cheese, spinach, milk
Difficulty: Easy
Make Ahead: Yes! Reheat in microwave or oven
Freezer Friendly: Yes. Up to 2 months

This past weekend, we had an awesome time with some overnight guests. My sister and her husband were in town. They joined us at the beach for a fun couple of days of eating, drinking, and socializing.

I like to make a hearty breakfast for out-of-town guests. I whipped up my easy breakfast casserole with spinach and sausage early on Saturday morning.

Along with crumb topped blueberry muffin cake, breakfast was a hit. I love, love, love this casserole! It is so versatile. Adapt it to use whatever breakfast meats, veggies, and cheese you have hand.

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Sausage Breakfast Casserole ingredients

The base of the breakfast casserole is the same. Change up the "filling" ingredients with your favorites. This combo of ingredients is my go~to for an easy sausage breakfast casserole.

salted butter
breakfast sausage
spinach
large eggs
whole milk
Dijon mustard
baking powder
kosher salt
pepper
cheddar cheese

How to Make Breakfast Sausage Casserole

Just some sauteing and mixing is all that is needed for the breakfast casserole.

Cook the sausage and spinach: First I sauté the sausage until it has some crispy bits and cooked through. To streamline the prep, stir in the spinach just before the sausage is done cooking.
Whisk the eggs, milk and seasonings: Next whisk the eggs along with milk, some mustard for a little kick, baking powder, kosher salt and pepper.
Combine the ingredients: Now for the easy part, combine the cooked sausage and spinach with the egg mixture and the shredded cheddar cheese. Pour into a buttered baking dish and cook until just set and puffed up in the middle.

Wasn't that easy? Let's eat!

breakfast casserole with sausage and spianch

can you make a breakfast casserole in advance?

Absolutely! That is why I love breakfast casseroles. If you are anything like me, I'm blurry eyed in the morning. But coffee first. I need all the help I can get.

After baking, completely cool, cover with plastic wrap. and store in the refrigerator for up to 3 days. When you would like a serve it, just reheat a piece on 60% power in the microwave for about 1 minute.

Alternately, you can prep the ingredients the day or night before assemble the casserole in the morning.

Brown the breakfast sausage, sauté the spinach and grate the cheddar cheese in advance. Store the ingredients in the refrigerator, and they will be ready to go the morning you make the casserole. Just combine all the ingredients and in about 30 minutes breakfast is served.

why is my breakfast casserole runny?

It is important to precook the vegetables before adding them along with the other ingredients for a breakfast casserole. Vegetables contain a high percentage of water. When raw veggies cook in the casserole, they release the water and make your breakfast too liquidy. Giving the vegetables a quick sauté will solve this problem.

Can You Freeze a Breakfast Casserole?

Yes! This breakfast casserole freezes beautifully. It's a great one to keep stashed in the freezer for busy mornings. This is exactly what my personal chef clients would do.

Bake and cool the casserole completely.
Wrap tightly in plastic wrap and then foil. For easy single servings, cut into slices and store in an air tight container.
Freeze for up to 2 months.
To serve, thaw in the refrigerator overnight. Heat individual servings in the microwave at 60 percent power for 1 minute. Continue heating at 30 second intervals until the egg bake hot. Alternately, warm the whole casserole covered in a 350 degree F oven for 20 to 25 minutes.

slice of breakfast casserole with sausage and cheese

variations for Easy Breakfast Casseroles

The breakfast casserole has a few basic ingredients (which you most likely have on hand) including eggs, milk, Dijon mustard, baking powder, kosher salt and pepper. The recipe is very forgiving. Change up the add-in ingredients to make it include your favorites. Some options include

cooked and crumbled bacon
diced ham
diced Canadian bacon
Swiss, pepper jack or herb goat cheese
steamed broccoli or asparagus
sautéed mushrooms or zucchini

A few of my readers have gotten creative with this recipe. Here are a few of their suggestions.

Tater tot topped: One reader baked the egg casserole for 15 minutes, added a layer of shredded cheese and par baked tater tots. Then they finished baking the casserole for another 15 minutes.
Egg muffin version: For individual portions, bake in a well greased nonstick muffin tin instead of a baking dish. Keep the same oven temperature. Check for doneness a few minutes earlier since the muffins bake faster than a whole casserole.
Extra sausage and bacon: If you can't decide between the two, add both! Cook the bacon along with the sausage before adding it along with the other ingredients.
Fresh tomatoes: A reader added chopped fresh tomatoes for a pop of color and flavor.