I can’t think of a better way to start the day than with a slice of this easy Breakfast Casserole. This recipe is loaded with eggs, sausage, spinach, peppers, and of course, cheese! A slice of this veggie and protein loaded casserole will keep you full for hours. No more “2nd breakfast” at 10 am. 🤣

A fork cutting into a slice of breakfast casserole.

Breakfast is my favorite meal of the day. This blog is proof of that. I have so many breakfast recipes you need to try! A few of my favorites are:

Easy Make Ahead Breakfast

What is breakfast casserole? It’s a breakfast dish made of primarily eggs, cheese, and in this case, sausage and vegetables. This recipe is loaded with onions, bell peppers, and spinach to be exact.

Sour cream (and a splash of milk) is added to make a creamy and fluffy texture.

I’m particularly fond of this recipe because you can make it the night before! Think about all of the scenarios when you’ll make this… Christmas, Thanksgiving, Fathers Day, (Mothers Day), Easter, TOMORROW!

It’s easy and delicious. Everyone will love it.

A slice of Breakfast Casserole being lifted out of the pan.

How to make Breakfast Casserole

  1. Whisk the eggs, sour cream, milk, and cheese until combined. A glass bowl full of whisked eggs, cheddar cheese, milk, and sour cream.
  2. Cook the sausage and onion until browned. Use a wooden spoon to break the sausage into small bite size pieces as it cooks. Drain excess grease. Overhead photo of browned sausage in a skillet.
  3. Transfer the sausage mixture to the bowl with the egg mixture.
  4. Cook the peppers. Add a drizzle of olive oil to the now empty skillet, stir in the bell peppers and cook for 2-3 minutes. Stir in the spinach and cook an additional 30 seconds. The spinach will wilt slightly. Diced red and green peppers, and chopped spinach in a skillet.
  5. Transfer the cooked peppers to the egg mixture. Use a wooden spoon or spatula and mix everything together. A large bowl full of breakfast casserole ingredients against a white background.
  6. Pour the mixture into a 13″x9″ inch pan. Bake for 30-40 minutes or until the edges are set and the center is barely jiggly. Mine baked 34 minutes. All ovens are different so keep an eye on it. A glass 13x9 inch pan full of breakfast casserole.
  7. Remove from the oven and let sit for 5 minutes before slicing and serving.
  8. Store leftovers covered in the fridge for 3-4 days. Reheat individual servings in the microwave.

Tips and FAQ about Breakfast Casserole

One of my biggest tips is to have the onion, peppers, and spinach chopped and diced before you begin. Doing so will make cooking this recipe a breeze.

Can breakfast casserole be made the night before? Yes. Make up until it needs to bake. Rather than bake cover the casserole and place in the fridge overnight. The next morning when ready to bake, remove the covering and bake according to recipes instructions.

What can one serve with breakfast casserole? A glass of milk or orange juice and a side of hash browns.

Variations and substitutions

Feel free to reduce the amount of sausage used. Rather than 2 lbs, opt for just 1 lb. Or if you want a healthier option use ground turkey in place of the sausage. Granted, the flavor will change with any substitutions made.

Add more spinach, more peppers, or any other vegetable of choice.

If you want a spicier breakfast casserole add diced jalapeños to the bell pepper mixture or use hot pork sausage.

Switch it up with the cheese! Use any cheese you have on hand Monterey Jack, Colby Jack, or Pepper Jack cheese works beautifully.

A slice of Breakfast Casserole on a plate.

More Mouthwatering Breakfast Recipes

A fork cutting into a slice of breakfast casserole.
Print Review
5 from 1 vote

Breakfast Casserole

This delicious breakfast casserole is loaded with sausage, eggs, spinach, peppers, and of course... cheese! One major bonus to this recipe is that it can be made the night before making breakfast the next day a total breeze.
Prep Time: 35 mins
Cook Time: 40 mins
Total Time: 1 hr 15 mins
Servings: 12 servings

Ingredients
 

  • 2 lbs pork sausage
  • 12 eggs
  • 1 cup sour cream - light or full fat
  • 1/4 cup milk
  • 1/2 cup onion - diced
  • 1 teaspoon olive oil
  • 1/2 green bell pepper - diced
  • 1/2 red bell pepper - diced
  • 1 cup spinach - chopped
  • 2 cups cheddar cheese - shredded

Instructions
 

  • Preheat oven to 350°F. Spray a 13x9 inch pan with cooking spray. Set aside. 
  • In a large bowl whisk the eggs, sour cream, milk, and shredded cheese until combined.
  • In a large skillet over medium heat add the sausage and onion and cook until browned, using a wooden spoon to break the sausage into small pieces as it cooks. Drain excess grease. 
  • Add the sausage to the egg mixture. 
  • In the now empty skillet add the olive oil and bell peppers. Cook for 2-3 minutes, then stir in the spinach and cook for 30 seconds. Spinach will wilt slightly. Remove from the heat. 
  • Transfer the cooked peppers to the egg mixture. Use a wooden spoon or spatula and mix everything together. 
  • Pour the mixture into the 13x9 inch pan. Bake for 30-45 minutes or until the edges are set and the center is barely jiggly. 
  • Remove from the oven, let sit for 5 minutes. Slice and serve. 
  • Store leftovers covered in the fridge for 3-4 days. Reheat individual servings in the microwave. 

Notes

To make ahead, prep the casserole up until baking point. Cover and place in the fridge. The next morning, remove the covering and bake as directed. 

Nutrition

Calories: 417kcal (21%)Carbohydrates: 3g (1%)Protein: 22g (44%)Fat: 35g (54%)Saturated Fat: 14g (70%)Cholesterol: 248mg (83%)Sodium: 680mg (28%)Potassium: 343mg (10%)Fiber: 1g (4%)Sugar: 2g (2%)Vitamin A: 1019IU (20%)Vitamin C: 12mg (15%)Calcium: 198mg (20%)Iron: 2mg (11%)
Course: Breakfast
Cuisine: American
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