Name: Overnight Sausage and Egg Breakfast Casserole Recipe
Prep time: 20 min
Cook time: 45 min
Total time: PT-494209H55M56S
Cuisine: American
Ingredients: ½ green or red bell pepper, diced; ½ medium onion, diced; 1 pound bulk sausage (your choice of mild to hot); 6 slices white bread, cubed; 8 ounces sharp cheddar cheese, grated; 8 eggs, beaten; 2 cups milk; 1 teaspoon dry mustard powder; ½ teaspoon salt; ½ teaspoon ground black pepper

Print Recipe· 4.3 from 10 reviews

If you have been searching for a comforting, hearty, and truly effortless breakfast that you can prepare ahead of time, then look no further than this Overnight Sausage and Egg Breakfast Casserole Recipe. This dish is a fabulous way to gather loved ones around the table on busy mornings or lazy weekends, combining savory sausage, fluffy eggs, melty cheese, and soft bread cubes all soaked in a flavorful custard. It’s the kind of breakfast that feels warm and indulgent without demanding hours in the kitchen, making it perfect for mornings when you just want to sit back with your coffee and enjoy every bite.

Ingredients You’ll Need

The image shows nine cooking ingredients arranged neatly on a white marbled surface. Starting from the top left, there is a clear glass measuring cup filled with white milk. To the right, there is a rectangular white container holding seven brown eggs stacked in two layers. Next to the eggs is a small clear bowl filled with finely chopped white onion pieces. Below the milk is a block of bright orange cheddar cheese resting on a silver grater with a black handle. To the right of the cheese, there is a small clear bowl filled with small red diced bell pepper pieces. Below the onion bowl, there is a small clear bowl filled with light brown dry mustard powder. Near the center bottom, there is a small clear bowl containing dark ground pepper and another small clear bowl with white salt. At the bottom left is a clear bowl filled with chunks of raw sausage meat, slightly pink and coarse. On the right bottom side, there is a small stack of white sliced bread placed on a square wooden cutting board with a handle. The items are evenly spaced and well organized. Photo taken with an iphone --ar 4:5 --v 7

Keeping things simple is the key to making this casserole truly shine. Each ingredient plays a crucial role in bringing the dish together by balancing tastes, textures, and colors that greet you with joy at mealtime.

1/2 green or red bell pepper (diced): Adds a sweet crunch and vibrant color to brighten the casserole.
1/2 medium onion (diced): Infuses the dish with aromatic depth and subtle sweetness once sautéed.
1 pound bulk sausage (mild to hot): Provides the savory, spicy foundation that makes this casserole irresistibly rich.
6 slices white bread (cubed): Acts as a soft, absorbent base that soaks up all the goodness from the egg custard.
8 ounces sharp cheddar cheese (grated): Melts beautifully into each bite, giving sharp, creamy flavor and gooey texture.
8 eggs (beaten): Creates the fluffy, protein-packed custard binding all ingredients together.
2 cups milk: Lightens the custard and keeps it moist and tender after baking.
1 teaspoon dry mustard powder: Enhances flavor with a gentle zing that complements the sausage and cheese.
1/2 teaspoon salt: Balances all the flavors without overpowering the other ingredients.
1/2 teaspoon ground black pepper: Adds just the right hint of warmth and spice.

How to Make Overnight Sausage and Egg Breakfast Casserole Recipe

Step 1: Cook the Vegetables and Sausage

Begin by heating a large skillet over medium-high heat and cook the diced bell pepper, onion, and sausage together. Stir frequently until the sausage is browned and no pink remains. Once cooked, drain any excess grease by placing the mixture on paper towels. This step is essential for achieving that perfectly savory flavor without too much oil.

Step 2: Prepare Bread and Cheese

Next, cut the white bread into roughly ½-inch cubes, which will soak up the egg mixture ideally. Grate your sharp cheddar cheese so it’s ready to add that amazing cheesy pull throughout the casserole.

Step 3: Whisk the Egg Mixture

In a large bowl, beat together the eggs, milk, dry mustard powder, salt, and pepper. This blend acts as the custard that will infuse the casserole with creaminess and help bind the ingredients in a luscious, fluffy texture.

Step 4: Layer the Ingredients

Take a 13×9-inch baking dish and lightly grease it. Begin by layering the bread cubes evenly on the bottom, then sprinkle the cooked sausage and veggies on top, and finish with a generous layer of cheddar cheese. Layering in this order ensures each bite has a perfect balance of bread, meat, and cheese.

Step 5: Add the Egg Mixture

Slowly pour the beaten egg and milk custard over the layered ingredients, making sure to cover all the bread cubes so they fully absorb the mixture. This step is crucial to give the casserole its signature custardy interior.

Step 6: Refrigerate Overnight

Cover the casserole with foil and refrigerate for at least 8 hours or overnight. This resting time allows the bread to soak up the egg mixture fully and the flavors to marry beautifully, making your morning baking super easy and rewarding.

Step 7: Bake and Enjoy

When morning comes, preheat your oven to 350°F (175°C), uncover the casserole, and bake for 45 minutes. The top should be golden and set while the inside remains tender and flavorful. Allow it to cool slightly before slicing for the best texture and ease of serving.

How to Serve Overnight Sausage and Egg Breakfast Casserole Recipe

A clear rectangular glass baking dish sits on a white marbled surface, filled with a baked casserole that has one visible thick layer. The top layer is golden-yellow melted cheese with small browned areas and scattered pieces of cooked ground meat and bits of red bell pepper mixed in, creating a textured and slightly uneven surface. The edges show slight browning where the cheese has crisped, while the middle remains soft and gooey. The casserole looks rich and hearty, filling the dish fully to the edges. photo taken with an iphone --ar 4:5 --v 7

Garnishes

Adding the right garnishes elevates this casserole from delicious to dazzling. Fresh chopped parsley or chives work wonderfully to add a pop of green and light freshness. For a rich finish, a dollop of sour cream or a drizzle of hot sauce can be just the touch you crave.

Side Dishes

This versatile casserole pairs well with a variety of sides. A simple mixed green salad with a light vinaigrette cuts through the richness beautifully, while fresh fruit like berries or melon adds a juicy, sweet contrast to the savory bake.

Creative Ways to Present

For a brunch gathering, serve the casserole in individual ramekins for a charming personal touch. You can also sprinkle extra cheese on top before baking for a bubbly cheese crust, or add sliced avocado and chives on each serving plate to impress your guests with fresh, colorful toppings.

Make Ahead and Storage

Storing Leftovers

Leftover casserole makes for fantastic next-day breakfasts or quick lunches. Store any cooled portions in an airtight container in the refrigerator for up to 3 days. Reheating gently helps maintain moisture and texture without drying out the eggs.

Freezing

If you want to make this casserole in bulk and freeze it, you absolutely can. Assemble the casserole as normal, then cover tightly with foil and plastic wrap before freezing. It will keep well for up to 2 months. When ready to bake, thaw overnight in the fridge and then follow the usual baking instructions.

Reheating

To reheat, place a portion on a microwave-safe plate and microwave for about 1 to 2 minutes until warmed through, or heat in a preheated oven at 350°F for 10 to 15 minutes. Cover with foil to avoid drying out and keep that lovely custard texture intact.

FAQs

Can I use different types of sausage for this recipe?

Absolutely! This Overnight Sausage and Egg Breakfast Casserole Recipe is very adaptable, so feel free to use mild, spicy, pork, turkey, or even plant-based sausage depending on your preference.

Do I have to use white bread or can I substitute?

White bread is preferred because of its soft texture and ability to soak up custard, but you can also use brioche, challah, or even whole wheat bread for a different flavor and nutrition profile.

Is it possible to make this casserole dairy-free?

Yes! Substitute the milk with a plant-based milk such as almond or oat milk, and use a dairy-free cheese alternative that melts well. The flavor and texture will still be delightful.

How far in advance can I assemble the casserole?

You can prepare and refrigerate the casserole for up to 24 hours before baking. The overnight soak is what gives it that perfect texture and flavor, so try not to let it sit too long beyond this.

Can I add other vegetables or ingredients to this casserole?

Definitely! Feel free to mix in mushrooms, spinach, or sun-dried tomatoes for extra flavor and nutrition. Just make sure to cook any additional veggies beforehand to avoid excess moisture.

Final Thoughts

Trust me when I say, this Overnight Sausage and Egg Breakfast Casserole Recipe is going to become your new go-to breakfast for busy mornings and special occasions alike. Its ease, flavor, and versatility make it a true crowd-pleaser that you can enjoy again and again. So gather your ingredients, prep it tonight, and wake up to a breakfast that feels like a warm hug on a plate. You won’t regret it!