Breakfast Sausage Casserole

There's something about a kitchen full of hungry people on a Saturday morning that makes you want to pull together something warm and generous. Years ago, I made this sausage casserole for a crowd showing up after an early hike, and I remember the smell of it baking—savory sausage mingling with melted cheese and toasted bread—drawing everyone to the kitchen before it was even out of the oven. That dish taught me that the best breakfast isn't about being fancy; it's about feeding people something that feels like comfort and care baked into every bite. Since then, this casserole has become my go-to when I need to feed a group without losing my mind in the kitchen.

I still think about the first time I tried the make-ahead version—prepping it the evening before, then waking to just slide the casserole into the oven while my housemates were still sleeping. By the time everyone shuffled downstairs, the kitchen was already warm and golden, and nobody had to wait. That's when I realized this recipe wasn't just food; it was permission to be relaxed and present instead of frazzled.

Ingredients

• 1 pound breakfast sausage, casings removed: The backbone of this dish—use good quality meat you'd actually eat on its own, because you'll taste every bit of it.
• 1 small yellow onion, finely chopped: Optional, but it adds a gentle sweetness that balances the salt of the sausage and cheese.
• 1/2 red bell pepper, diced: Also optional, but it brings color and a subtle brightness to each bite.
• 8 large eggs: Room temperature eggs whisk more smoothly, though it's not a dealbreaker if you forget.
• 2 cups whole milk: This is your liquid that transforms the bread into something creamy and custardy—don't skimp on quality here.
• 2 cups shredded cheddar cheese: Sharp cheddar gives more flavor than mild, and it melts into those bread cubes beautifully.
• 1/2 cup shredded mozzarella cheese: Adds stretch and a subtle creaminess; part of what makes the whole thing cohesive.
• 6 cups day-old bread, cut into 1-inch cubes: Stale bread is essential—it soaks up the egg mixture without turning mushy.
• 1 teaspoon salt, 1/2 teaspoon black pepper, 1/2 teaspoon dried mustard powder, 1/4 teaspoon paprika: These seasonings work quietly but make the difference between a good casserole and one people ask you to make again.

Instructions

Heat the oven and grease your dish:

Set the oven to 350°F and use butter or nonstick spray on a 9x13-inch baking dish—this seems basic, but it's the difference between sliding the casserole out easily later and scraping at the edges.

Brown the sausage and vegetables:

In a large skillet over medium heat, crumble the sausage with a spoon and cook until it loses its pink color, about 5 to 7 minutes. If you're using onion and bell pepper, add them now and let them soften for another few minutes, then drain off any excess fat so the casserole isn't greasy.

Layer the bread and sausage:

Spread your bread cubes evenly across the bottom of the baking dish, then scatter the cooked sausage (and vegetables, if using) over the top—this layering is casual; it doesn't need to be perfect.

Make the custard mixture:

Whisk together the eggs, milk, salt, pepper, mustard powder, and paprika in a large bowl until it looks smooth and uniform. Stir in 1 1/2 cups of the cheddar and all the mozzarella, then taste it—a tiny spoonful to make sure the seasoning feels right to you.

Pour and soak:

Pour the egg mixture evenly over the bread and sausage, then gently press the bread cubes down with the back of a spoon so they drink in the liquid. Some pieces will float, some will sink; that's fine and actually helps everything bake evenly.

Add the finishing cheese:

Scatter the remaining cheddar across the top—this becomes golden and slightly crispy, adding a little texture to the top layer.

Bake covered, then uncovered:

Cover the dish with foil and bake for 30 minutes, then remove the foil and bake another 15 minutes until the top is golden brown and the center feels set when you gently jiggle the pan. A knife inserted into the center should come out clean or with just a tiny bit of custard clinging to it.

Rest before serving:

Let the casserole sit for 10 minutes out of the oven—this helps it set up and makes slicing cleaner and less messy.

Save to Pinterest

I learned the importance of that resting time the hard way, slicing too eagerly and ending up with a beautiful mess on the plate instead of neat squares. Now I use those 10 minutes to set the table or brew more coffee, and it pays off every single time.

Make-Ahead Magic

This is where the casserole really shines—assemble everything the night before, cover it tightly, and refrigerate. In the morning, you only have to preheat the oven and slide it in, which feels like cheating in the best way. Just add about 10 extra minutes to the baking time since it's coming straight from the fridge, and you'll still have a warm, impressive breakfast ready before most people are fully awake.

Flavor Variations and Add-Ins

Once you've made this basic version a time or two, you'll start seeing opportunities to play. Swap the cheddar for Swiss cheese if you want something milder and nuttier, or use pepper jack if you like heat threading through every bite. Sautéed mushrooms or fresh spinach stirred in with the sausage adds earthiness and vegetables without changing the fundamental structure of the dish. A handful of fresh herbs like dill or chives scattered on top just before serving brings brightness that contrasts with the richness underneath.

Serving and Storage Suggestions

Serve this warm from the oven with salsa or hot sauce on the side, which adds a little acid and spice that cuts through the richness. Leftovers keep in the refrigerator for three days and can be reheated gently in a 300°F oven, or even eaten cold straight from the fridge on a lazy morning.

• If you want to freeze portions, cool the casserole completely, then wrap individual slices tightly and freeze for up to a month.
• A dollop of sour cream on the side is an underrated addition that few people expect but everyone loves.
• This casserole is forgiving enough to serve for dinner too—it's warm, filling, and tastes just as good at 6 p.m. as it does at 8 a.m.

Save to Pinterest

This casserole has fed my friends, my family, and complete strangers at potlucks, and it never fails to make people feel cared for. Make it once and you'll understand why it's become a staple in kitchens everywhere.

Recipe Q&A

→ Can I prepare the dish ahead of time?

Yes, assemble the layers the night before, cover tightly, and refrigerate. Bake with an extra 10 minutes if baking from cold.

→ What type of bread works best?

Day-old French or sourdough bread cut into cubes provides a sturdy, golden base that absorbs the egg mixture well.

→ Can I substitute the cheeses?

Absolutely, Swiss or pepper jack cheese can replace cheddar for a different flavor profile.

→ Are vegetables optional in this dish?

Onion and red bell pepper add extra flavor and texture but can be omitted if preferred.

→ How do I ensure the bake sets properly?

Baking covered first and then uncovered allows the center to cook evenly and the top to brown beautifully.

→ What spices enhance this dish?

Paprika and mustard powder bring warmth and depth without overpowering the savory sausage and cheese.