Overnight Egg Casserole

Overnight Egg Casserole is a hearty, easy breakfast that everyone will love. It’s loaded with eggs, ham, onion, bell peppers, cheese, and more.

image of a overnight egg casserole in a glass baking dish

If you’re looking for the ultimate breakfast then look no further. You’ve found it here. We love to make this casserole when we’re in the mood for an extra-hearty breakfast or when we’re having company over. It’s super hearty and super easy. It doesn’t get better than that!

scoop of overnight egg casserole in a ceramic ramekin with a glass of orange juice in the background

❤️ Why You’ll Love This Recipe

  • It uses simple ingredients that you can find in your kitchen and the grocery store.
  • It’s an easy recipe that you can prep the night before.
  • It’s loaded with all of your favorite breakfast flavors.


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This recipe uses simple ingredients that are readily available at your local grocery store. There’s nothing fancy here, just delicious flavor. Check out the recipe card at the end of the post for exact quantities.

  • Eggs
  • Milk
  • Dijon mustard
  • Diced ham
  • Diced onion
  • Diced green and red bell peppers
  • White bread
  • Shredded cheddar cheese
  • Shredded Pepper Jack cheese
  • Scallions

🔪 How to Make Overnight Egg Casserole

Making this recipe is incredibly easy. It only takes a few minutes of prep the night before and about an hour in the oven in the morning. That’s it!

ingredients layered in a glass baking dish ready for the fridge.

Step 1: Make the Casserole

Whisk the eggs, milk, and mustard together in a large bowl. Then, add ham, onion, 3/4 of the peppers, and bread to the egg mixture. Pour into a sprayed 9×13 baking dish and top with the cheese and remaining bell peppers.

Step 2: Refrigerate

Cover the dish with plastic wrap and refrigerate overnight or up to 12 hours until ready to bake.

off center image of a overnight egg casserole in a glass baking dish

Step 3: Bake

Let the casserole sit on the counter for about 30 minutes to take the chill off. During that time, preheat the oven to 350. Bake the casserole for 55 to 60 minutes. Cover with foil if it begins to brown too quickly. Top with scallions and enjoy!


Do you want to change up this recipe and make it your own? Here are some ways that you can do that!

  • Spicy – Try adding red pepper flakes, diced jalapenos, or diced chiles to the mixture for a kick of heat.
  • Breakfast Meat – Try adding cooked sausage or bacon to the mixture.
  • White Bread – Use any kind of bread in this recipe.

If you think this sounds good, then check out our overnight croissant breakfast casserole with gravy.

scoop of overnight egg casserole in a ceramic ramekin

🥄 Equipment

  • Measuring cups and spoons
  • Knife
  • Cutting board
  • Baking dish
  • Foil
  • Mixing bowl
  • Whisk

🥫 Storage

Store this casserole in an air-tight container for up to 4 days in the refrigerator.

💭 Tips

  • To ensure proper baking, be sure you let the casserole sit at from temperature for about a half hour.
  • Check your casserole 20 to 30 minutes into baking to ensure that it isn’t browning too quickly.
  • Thoroughly coat your baking dish with non-stick spray to ensure the casserole comes out easily.

⁉️ FAQ

Do you have questions about this recipe? Here are the answers to the most commonly asked questions.

What is a breakfast casserole?

Breakfast casseroles are made with a base of eggs, cheese, milk, and bread. Then, whatever breakfast ingredients you choose are added and the whole thing is baked.

What is a casserole?

A casserole is any food cooked in a deep, wide dish.

What can I add to a breakfast casserole?

You can add all kinds of things! Try adding any of your favorite breakfast meats, onions, bell peppers, mushrooms, and of course, lots of cheese!

🍽 More Recipes

Do you enjoy casserole? Then try these delicious recipes:

📌 PIN IT!!

overnight egg casserole in a glass baking dish with the name in text for pinterest

🧾Recipe Card

Want to make this recipe? Print the recipe card below, or pin this recipe, so you can find it later.

image of a overnight egg casserole in a glass baking dish

Overnight Egg Casserole

This overnight egg casserole is an easy, hearty breakfast that you can prepare the night before and just pop in the oven in the morning.
3 from 6 votes
Print Pin Rate
Course: Breakfast
Cuisine: American
Prep Time: 10 minutes
Cook Time: 55 minutes
Chill Time: 8 hours 30 minutes
Total Time: 9 hours 35 minutes
Servings: 8 Servings
Calories: 353kcal


  • Measuring Cups and Spoons
  • Knife
  • Cutting board
  • Baking dish
  • Foil
  • Mixing Bowl
  • Whisk


  • 9 eggs
  • 3 cups milk
  • 2 teaspoons dijon mustard
  • 1 pound diced ham
  • 1 small onion diced
  • 1 small green bell pepper diced, divided
  • 1 small red bell pepper diced, divided
  • 9 slices white bread torn into pieces
  • 1 cup shredded cheddar cheese
  • 1 cup shredded pepper jack cheese
  • Scallions for topping optional


  • In a large bowl whisk together your eggs, milk and dijon mustard.
  • Reserve a quarter of your diced red bell pepper and a quarter of your green bell pepper.
  • To the egg mixture stir in your ham, onion, peppers, and bread.
  • Butter or spray a 9×13 baking dish.
  • Pour in the mixture.
  • Top with the cheeses and the reserved bell peppers.
  • Cover with plastic wrap and place in the fridge overnight or up to 12 hours.
  • When ready to bake preheat oven to 350 degrees.
  • Let the casserole sit on counter for 30 minutes to take the chill of while the oven preheats.
  • Bake the casserole at 350 for 55-60 minutes, you may need to cover it with foil if it begins to brown too quickly.
  • Remove from oven and serve!
  • Top with scallions if desired.


Any nutritional data I provide is an approximation and actual dietary information can vary based on ingredients and proportion sizes.


Serving: 1Serving | Calories: 353kcal | Carbohydrates: 23g | Protein: 29g | Fat: 16g | Saturated Fat: 7g | Polyunsaturated Fat: 2g | Monounsaturated Fat: 4g | Trans Fat: 0.03g | Cholesterol: 241mg | Sodium: 1165mg | Potassium: 339mg | Fiber: 2g | Sugar: 9g | Vitamin A: 1076IU | Vitamin C: 32mg | Calcium: 370mg | Iron: 2mg
3 from 6 votes (6 ratings without comment)

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