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–+ servings
Overnight Breakfast Casserole 1

Overnight Breakfast Casserole

This make-ahead breakfast bake is a game-changer for busy mornings, holiday gatherings, or when hosting overnight guests. By assembling everything the evening before, you'll wake up to a stress-free morning with only the delightful aroma of a home-cooked meal filling your kitchen.
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Prep Time 20 minutes
Cook Time 50 minutes
Chilling Time 8 minutes
Total Time 9 minutes
Course Breakfast
Cuisine American
Servings 8 servings
Calories 385 kcal

Equipment

  • 9x13-inch Baking Dish
  • Large Skillet
  • Mixing Bowl

Ingredients
  

Casserole Base

  • 1 pound breakfast sausage mild or spicy, depending on preference
  • 8 large eggs
  • 2 cups whole milk substitute 2% for a lighter option
  • 1 tsp dried mustard
  • 1/2 tsp salt
  • 1/4 tsp black pepper
  • 6 slices bread cubed (sourdough or brioche work beautifully)
  • 2 cups shredded cheddar cheese or a mix of cheddar and Gruyère

Vegetables

  • 1 red bell pepper diced
  • 1 green bell pepper diced
  • 1 medium onion finely chopped
  • 2 cloves garlic minced
  • 1 tbsp fresh parsley chopped, for garnish

Instructions
 

  • Brown the breakfast sausage in a large skillet over medium heat, breaking it into small crumbles as it cooks (5-7 minutes). Drain any excess grease.
  • In the same skillet, add a small amount of olive oil and sauté the diced onions until translucent (about 3 minutes). Add the bell peppers and continue cooking for another 3-4 minutes until softened. Add minced garlic for the final 30 seconds.
  • In a large bowl, whisk together the eggs, milk, dried mustard, salt, and pepper until well combined.
  • Grease a 9×13-inch baking dish. Spread the cubed bread evenly across the bottom. Layer the cooked sausage and vegetable mixture over the bread, then sprinkle with 1½ cups of the shredded cheese, reserving ½ cup for later.
  • Pour the egg mixture evenly over everything, gently pressing down with a spatula to ensure all ingredients are moistened.
  • Cover the casserole tightly with plastic wrap or aluminum foil and refrigerate for at least 8 hours or overnight.
  • The next morning, remove the casserole from the refrigerator and let it sit at room temperature while your oven preheats to 350°F (175°C).
  • Remove the covering and bake for 45-50 minutes until the center is set and the top is golden brown. In the last 5 minutes of baking, sprinkle the remaining ½ cup of cheese on top and return to the oven until melted.
  • Let stand for 5 minutes before cutting. Garnish with fresh chopped parsley before serving.

Notes

- Day-old, slightly dried bread absorbs the egg mixture better than fresh bread.
- Store leftovers in an airtight container for up to 3 days in the refrigerator.
- For a vegetarian option: Replace sausage with 2 cups of sautéed mushrooms and an extra bell pepper.
- For a gluten-free version: Substitute gluten-free bread or 3 cups of shredded hash browns.
- For dairy-free: Use unsweetened almond milk and dairy-free cheese alternatives.

Nutrition

Calories: 385kcalCarbohydrates: 18gProtein: 22gFat: 25gSaturated Fat: 12gCholesterol: 220mgSodium: 680mgFiber: 1.5gSugar: 4gCalcium: 25mgIron: 15mg
Keyword Breakfast Casserole, Overnight Breakfast, Make-Ahead Breakfast, Breakfast Bake
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