The Ultimate Overnight Breakfast Casserole Recipe
Introduction
The Ultimate Overnight Breakfast Casserole is a hearty and convenient dish perfect for busy mornings or brunch gatherings. Packed with sausage, cheese, and crispy hash browns, it’s a crowd-pleaser that you prepare the night before and simply bake in the morning.

Ingredients
- 1 pound breakfast sausage
- 1 package frozen hash browns (about 30 oz)
- 8 large eggs
- 1 cup milk
- 1 cup sour cream
- 2 cups shredded cheddar cheese
- 1/2 teaspoon salt
- 1/4 teaspoon black pepper
- 1/4 cup chopped green onions
Instructions
- Step 1: Cook the sausage in a skillet over medium heat until browned. Set aside to cool.
- Step 2: In a large bowl, whisk together the eggs, milk, sour cream, salt, and pepper until smooth.
- Step 3: Grease a 9×13 baking dish and layer half of the hash browns, half the sausage, and a layer of cheese.
- Step 4: Repeat the layers with the remaining hash browns, sausage, and cheese.
- Step 5: Pour the egg mixture evenly over the top of the layered ingredients.
- Step 6: Cover with foil and refrigerate overnight.
- Step 7: Preheat the oven to 350°F in the morning and bake the casserole, covered, for 45 minutes.
- Step 8: Remove the foil and bake an additional 20–25 minutes until golden and fully set.
- Step 9: Top with chopped green onions and serve warm.
Tips & Variations
- You can substitute bacon or ham for the sausage for a different flavor.
- Add vegetables like bell peppers or spinach for a healthier version.
- Use a mix of cheddar and mozzarella cheese for extra creaminess.
- Let the casserole sit for 5 minutes before slicing to keep it from falling apart.
Storage
Store leftover casserole in an airtight container in the refrigerator for up to 3 days. Reheat individual portions in the microwave or oven until warmed through. For longer storage, freeze the casserole for up to 2 months and thaw overnight before reheating.
How to Serve

Serve this delicious recipe with your favorite sides.
FAQs
Can I prepare this casserole without freezing it overnight?
Yes, you can bake it immediately after assembling, but the flavors will meld better and the texture will improve after chilling overnight.
Can I use fresh potatoes instead of frozen hash browns?
Fresh potatoes can be used if peeled and shredded, but be sure to squeeze out excess moisture to avoid a soggy casserole.
PrintThe Ultimate Overnight Breakfast Casserole Recipe
The Ultimate Overnight Breakfast Casserole is a hearty and convenient dish perfect for busy mornings. This savory casserole features layers of crispy hash browns, flavorful breakfast sausage, and melted cheddar cheese bound together with a creamy egg and sour cream mixture. Prepared the night before and baked in the morning, it offers a delicious and comforting start to your day with minimal effort.
- Prep Time: 15 minutes
- Cook Time: 65 minutes
- Total Time: 8 hours 20 minutes (including overnight refrigeration and baking time)
- Yield: 8 servings 1x
- Category: Breakfast
- Method: Baking
- Cuisine: American
Ingredients
Meat
- 1 pound breakfast sausage
Vegetables
- 1 package frozen hash browns (about 30 oz)
- 1/4 cup chopped green onions
Dairy & Eggs
- 8 large eggs
- 1 cup milk
- 1 cup sour cream
- 2 cups shredded cheddar cheese
Seasonings
- 1/2 teaspoon salt
- 1/4 teaspoon black pepper
Instructions
- Cook the Sausage: Heat a skillet over medium heat and cook the breakfast sausage until browned and fully cooked through. Once done, drain excess fat if necessary and set the sausage aside to cool slightly.
- Prepare Egg Mixture: In a large mixing bowl, whisk together the eggs, milk, sour cream, salt, and black pepper until the mixture is smooth and well combined.
- Layer Ingredients: Grease a 9×13 inch baking dish thoroughly. Begin by spreading half of the frozen hash browns evenly on the bottom. Then layer half of the cooked sausage over the hash browns, followed by a layer of shredded cheddar cheese.
- Repeat Layers: Repeat the layering process with the remaining hash browns, sausage, and cheese, creating a second set of layers.
- Add Egg Mixture: Pour the prepared egg, milk, and sour cream mixture evenly over the layered ingredients to soak through.
- Refrigerate Overnight: Cover the baking dish tightly with aluminum foil and place it in the refrigerator overnight to allow the flavors to meld and the casserole to set.
- Bake Covered: The next morning, preheat your oven to 350°F (175°C). Bake the casserole covered with foil for 45 minutes to cook through gently and retain moisture.
- Bake Uncovered: Remove the foil and continue baking the casserole for an additional 20 to 25 minutes, or until the top is golden brown and the casserole is fully set.
- Garnish and Serve: Once baked, remove the casserole from the oven and let it cool for about 5 minutes. Sprinkle the chopped green onions on top for a fresh finish. Slice and serve warm.
Notes
- You can substitute bacon or ham for the breakfast sausage to vary the flavor.
- Adding vegetables like bell peppers or spinach makes this casserole healthier and adds extra texture.
- For a creamier texture, use a combination of cheddar and mozzarella cheese.
- Allow the casserole to rest for 5 minutes after baking before slicing to help it hold its shape better.
Keywords: overnight breakfast casserole, breakfast casserole, hash brown casserole, sausage casserole, make ahead breakfast, cheesy breakfast bake

