Description

This hearty Overnight Sausage and Egg Casserole is the ultimate make-ahead breakfast miracle! Savory sausage, cubed bread soaked in a rich egg custard, and plenty of melty cheese create a golden-brown masterpiece that’s perfect for holiday mornings, weekend brunches, or feeding a hungry crowd. Prep it the night before and wake up to an effortless breakfast that’ll have everyone asking for seconds!

Ingredients

Scale

1 pound breakfast sausage (mild or spicy—your call!)
8 large eggs
2 cups whole milk (or half-and-half for extra richness)
1 teaspoon kosher salt
½ teaspoon freshly ground black pepper
1 teaspoon dry mustard powder
1 teaspoon fresh thyme leaves (or ½ teaspoon dried)
6 cups cubed day-old bread (French loaf or sourdough work best)
2 cups shredded sharp cheddar cheese
1 cup shredded mozzarella cheese
2 tablespoons chopped fresh chives or green onions (plus extra for garnish)

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Instructions

Preheat a skillet over medium heat. Crumble in your breakfast sausage and cook until no longer pink, about 7 minutes.
Drain off excess fat and spread the sausage in the bottom of a lightly greased 9×13″ baking dish.
While the sausage is cooking, cube your day-old bread into roughly 1″ pieces. Toss them into a large bowl.
In a separate mixing bowl, whisk together eggs, milk, salt, pepper, mustard powder, and thyme until fully combined and slightly frothy.
Add the cubed bread to the baking dish, layering it evenly over the sausage.
Sprinkle 1½ cups of the cheddar and all the mozzarella on top of the bread.
Carefully pour your egg mixture over everything, making sure the bread soaks up all that goodness.
Press down lightly on the bread to help it absorb the custard.
Cover the dish tightly with plastic wrap and refrigerate for at least 6 hours, ideally overnight (up to 12 hours).
In the morning, preheat your oven to 350°F (175°C) and remove the casserole from the refrigerator.
Uncover the casserole, sprinkle the remaining ½ cup of cheddar on top, and bake for 45–55 minutes, until the center is set and the top is golden brown.
Let the casserole rest for 5–10 minutes before serving.
Sprinkle with additional chopped chives or green onions.
Cut into squares and serve hot, with optional hot sauce or maple syrup on the side.

Notes

Veggie Boost: Fold in a cup of sautéed bell peppers and onions with the sausage.
Make It Lighter: Swap half the milk for low-fat milk and use turkey sausage.
Spicy Kick: Stir in a teaspoon of red pepper flakes or use hot sausage.
Cheese Swap: Pepper Jack or Gruyère add a lovely twist.
For a make-ahead option beyond overnight, you can freeze the unbaked casserole for up to 1 month. Thaw completely in the refrigerator before baking.
Day-old bread works best as it absorbs more egg mixture without getting soggy.

Prep Time: 20 minutes
Cook Time: 55 minutes
Category: Breakfast, Brunch
Method: Baking
Cuisine: American

Nutrition

Serving Size: 1 square (⅛ of casserole)
Calories: 425
Sugar: 3g
Sodium: 890mg
Fat: 28g
Saturated Fat: 12g
Unsaturated Fat: 14g
Trans Fat: 0g
Carbohydrates: 18g
Fiber: 1g
Protein: 25g
Cholesterol: 210mg