An overnight breakfast casserole is the secret to a calm holiday morning. You assemble it the night before, let the bread soak up an eggy custard in the fridge, and bake it while you open presents.
This make ahead sausage egg breakfast casserole layers savory sausage, cubed bread, and sharp cheddar for a hearty, cozy brunch dish. It is the ultimate Christmas morning breakfast casserole that feeds a crowd with almost no morning work.
Recipe at a Glance
| Prep Time | 20 minutes (plus overnight chilling) |
| Cook Time | 50 minutes |
| Total Time | About 8 hours (mostly chilling) |
| Servings | 8 servings |
| Category | Breakfast / Brunch |
Why You’ll Love This Overnight Breakfast Casserole
- Assembled the night before for an effortless morning
- Savory sausage, fluffy eggs, and melty cheddar in every bite
- Feeds a crowd for holidays and brunches
- Simple, affordable ingredients
- Easy to customize with veggies and cheeses
Ingredients You’ll Need
- 1 pound breakfast sausage
- 6 cups (about ½ loaf) day-old bread, cut into 1-inch cubes
- 2 cups shredded sharp cheddar cheese, divided
- 8 large eggs and 2 cups whole milk
- 1 teaspoon salt, 1 teaspoon dry mustard powder, and ½ teaspoon black pepper
- 3 green onions, sliced (optional)
How to Make an Easy Overnight Sausage Breakfast Casserole
- Grease a 9×13-inch baking dish and cook the sausage in a large skillet over medium heat for 8 to 10 minutes, breaking it up, until browned. Drain the fat.
- Spread the bread cubes in the baking dish and top with the cooked sausage and half of the cheese.
- Whisk the eggs, milk, salt, mustard powder, and pepper together until smooth and pour evenly over the bread.
- Cover tightly with plastic wrap and refrigerate for at least 8 hours or overnight.
- In the morning, preheat the oven to 350°F (175°C), remove the plastic wrap, and sprinkle with the remaining cheese and green onions.
- Bake for 45 to 55 minutes until puffed, golden, and set in the center, then rest 10 minutes before slicing.
Tips for the Best Make-Ahead Sausage Egg Breakfast Casserole
- Use day-old or lightly toasted bread so it soaks up the custard without turning mushy.
- Press the bread down gently so it absorbs the egg mixture evenly.
- Let the casserole sit on the counter for 20 minutes before baking so it cooks evenly.
- Cover loosely with foil if the top browns too quickly.
- Check that the center reaches 160°F for food safety.
Variations to Try: Breakfast Casserole Ideas
- Swap sausage for bacon, ham, or sauteed mushrooms.
- Add sauteed peppers, onions, or spinach for veggies.
- Use pepper jack cheese for a spicy kick.
- Make it a French toast bake with cinnamon and maple syrup.
How to Store It
Refrigerate leftovers in an airtight container for up to 4 days and reheat in the microwave or a 350°F oven. Freeze baked slices individually for up to 2 months and reheat from frozen.
Frequently Asked Questions
Can I make breakfast casserole the night before?
Yes. That is the point of an overnight casserole. Assemble it, cover, refrigerate, and bake in the morning.
Can I freeze an overnight breakfast casserole?
Yes. Freeze the baked casserole in slices for up to 2 months, or assemble it and freeze unbaked, then thaw overnight in the fridge.
What bread is best for breakfast casserole?
Sturdy day-old bread like Italian, French, or brioche works best because it holds its shape.
How do you know when breakfast casserole is done?
It should be puffed and golden, with no liquid in the center, and reach 160°F inside.
Overnight Sausage Breakfast Casserole
Ingredients
Equipment
Method
- Step 1: Cook and drain the sausage and grease a 9x13-inch dish.
- Step 2: Layer the bread, sausage, and half the cheese in the dish.
- Step 3: Whisk the eggs, milk, and seasonings and pour over the bread.
- Step 4: Cover and refrigerate overnight.
- Tip: Chill at least 8 hours.
- Step 5: Top with the remaining cheese and green onions and bake at 350°F for 45 to 55 minutes.
- Tip: Cover with foil if it browns too fast.
- Step 6: Rest 10 minutes before slicing.
Notes
The casserole is done when it reaches 160°F in the center.