Breakfast Sausage Casserole

The smell of sausage cooking in butter always pulls me into the kitchen, no matter what I am doing. My aunt used to make this casserole every Christmas morning, and the entire house would wake up to the most incredible aroma. She never measured anything, just dumped ingredients into her favorite chipped baking dish, and somehow it always turned out perfect. I have tried to recreate that magic ever since, watching the bread transform into golden custard in the oven.

Last year I made this for my book club when we met early to discuss a mystery novel. Everyone was still groggy from the drive, but within minutes of the casserole coming out of the oven, the kitchen was full of people stealing forkfuls while they waited for coffee. One friend asked for the recipe before she even finished her first slice.

Ingredients

• Breakfast sausage: The real flavor foundation here, so use the good stuff your family actually likes eating plain
• Day-old bread cubes: Sturdy bread holds up better than fresh, giving you those perfect custardy pockets instead of mush
• Eggs and whole milk: Together they create that rich, creamy texture that makes breakfast casserooles so irresistible
• Sharp cheddar and mozzarella: The cheddar brings the bold flavor while mozzarella adds that gorgeous melted cheese pull
• Dried mustard powder:Do not skip this, it adds a subtle depth that makes people ask what your secret ingredient is
• Paprika: Just enough to lend warmth and a beautiful golden color to the finished dish

Instructions

Get your oven ready:

Preheat to 350°F and butter a 9x13-inch baking dish thoroughly, getting into all the corners so nothing sticks.

Cook the sausage:

Brown it in a large skillet over medium heat, breaking it up with your spoon until it is cooked through, about 5 to 7 minutes.

Add the vegetables:

Toss in the onion and bell pepper if you are using them, cooking another 3 to 4 minutes until softened, then drain any excess fat.

Build the base:

Spread your bread cubes evenly in the buttered dish and top with the sausage mixture.

Whisk the custard:

Beat the eggs, milk, salt, pepper, mustard powder, and paprika in a large bowl until completely combined.

Add the cheese:

Stir in one and a half cups of cheddar with all the mozzarella until it is evenly distributed.

Combine and soak:

Pour the egg mixture over the bread and sausage, then gently press everything down so the bread soaks up all that liquid.

Bake with foil:

Cover tightly with foil and bake for 30 minutes to let everything steam together.

Get golden:

Remove the foil, sprinkle the remaining cheddar on top, and bake another 15 minutes until bubbly and set in the center.

Rest before serving:

Let it sit for 10 minutes so the custard firms up slightly and makes for cleaner slices.

Save

This became our go-to Christmas morning tradition after the year I tried making individual omelets for twelve people. Everyone was hungry, I was stressed, and breakfast took two hours. Now I assemble this the night before, and Christmas morning is just about coffee and opening presents while it bakes.

Make It Your Own

I have learned that breakfast casserooles are incredibly forgiving. Sometimes I throw in leftover roasted vegetables from dinner the night before, or swap in pepper jack for a little kick. The foundation stays the same, but you can adapt it to what your family actually enjoys eating.

Perfect Pairings

A fresh fruit salad on the side cuts through all that richness beautifully. In summer I use berries and stone fruit, but winter calls for oranges and pomegranate seeds. Hot coffee is essential, and mimosas never hurt if it is a special occasion.

Storage and Reheating

This casserole actually tastes better the next day when the flavors have had more time to meld. I store leftovers covered in the refrigerator for up to four days. Reheat individual portions in the microwave for about 2 minutes, or warm larger sections covered in foil at 325°F until heated through.

• Let the dish cool completely before covering to prevent condensation
• Freeze portions wrapped tightly for up to 2 months
• Add a splash of milk when reheating if it seems dry

Save

There is something so grounding about a breakfast that feeds everyone from one dish, no flipping required.

Questions & Answers

→ Can I prepare this casserole the night before?

Yes, assemble the entire casserole the night before, cover tightly, and refrigerate. In the morning, bake as directed, adding about 10 extra minutes since it will be cold from the fridge.

→ What type of bread works best?

Day-old French bread, sourdough, or artisan bread works excellently. Slightly stale bread absorbs the egg mixture better without becoming mushy. Avoid very soft fresh sandwich bread.

→ Can I make this without meat?

You can substitute the sausage with plant-based crumbles, or increase the vegetables like bell peppers, onions, spinach, or mushrooms. You may want to add extra cheese or seasonings to maintain richness.

→ How do I know when the casserole is done?

The casserole is finished when the center is set and no longer jiggles, the top is golden brown, and a knife inserted near the center comes out clean. The internal temperature should reach 160°F (71°C).

→ Can I freeze leftovers?

Yes, leftover portions freeze well for up to 2-3 months. Wrap individual slices tightly in plastic wrap and foil, then thaw overnight in the refrigerator before reheating in the microwave or oven.

→ What other cheese varieties work well?

Swiss, Gruyère, pepper jack, or Colby Jack all pair beautifully with the sausage. For extra flavor, try mixing half sharp cheddar with a milder cheese like Monterey Jack.