This Quick and Easy Overnight Italian Breakfast Casserole is perfect for weekend brunch, Christmas morning, or breakfast for dinner! Made with lots of veggies and Italian sausage, it’s so flavorful and delicious! Serve warm or cold!
Good morning! I hope you’re ready for breakfast. Because today we’re diving into the tastiest brunch casserole you’ll ever make! My family literally BEGS me to make this every weekend. And I happily comply because it couldn’t be easier!!! And it serves a crowd. Which means with our smaller household, we always have leftovers. And you know I LOVE leftovers.
Now, I know egg casserole isn’t the sexiest sounding recipe. But I pinky swear that if you give this humble casserole dish a try, you won’t regret it. So preheat your oven to 350 and let’s chat ingredients, ok?!
Easy Breakfast Casserole
This easy overnight Italian breakfast casserole is infinitely adaptable! Below you’ll find the ingredients I like to use, along with plenty of substitution ideas!
- Eggs (I suggest using the best quality eggs you can find! We love pasture raised eggs from the farmers market)
- Milk (use whole milk or, for a richer casserole dish, use heavy cream)
- Parmesan cheese (can easily be substituted with pepper jack, sharp cheddar, or any variety of cheese that tickles your fancy!)
- Salt and Pepper
- Olive Oil (If you’re in a pinch, use butter or refined coconut oil)
- Spinach (sub with kale or even swiss chard!)
- Red Bell Peppers (any color pepper will work!)
- Onion (we used a combination of red onion and yellow onion. even green onions could work!)
- Italian Sausage (hot Italian sausage or sweet Italian sausage work great! to make this a meat-free dish, simply omit the sausage. not a fan of sausage? use bacon instead!)
As you can see from the ingredient list above, I did not use bread cubes for this recipe. I know a lot of recipes do, but I find it completely unnecessary. But if you’re looking to serve a carb with this breakfast casserole, it goes great with my white cheddar, bacon, and apple biscuits!
How to make Breakfast Casserole
- Place a large skillet over medium heat and coat it with nonstick cooking spray or a little bit of olive oil. Add the sausage to the skillet and begin to break it up into small chunks. Cook sausage until it’s golden brown and no longer pink then drain any grease from the pan. Remove sausage from the pan and set aside until needed.
- In the same pan, add in the peppers, spinach, onion, garlic, rosemary, Italian seasoning, salt and pepper. Add a little extra olive oil if needed. Cook until veggies down until they’re tender. Toss the sausage back in the pan, and remove the pan from heat.
- In a large bowl combine the eggs, milk, cheese, salt, and pepper. Whisk until well combined. Set aside.
- Generously grease a 9×13 baking dish. Add half of the veggie and sausage mixture to the bottom of the pan.
- Then pour the egg mixture on top. Add remaining veggies and sausage and shake the pan gently. Cover casserole with saran wrap or aluminum foil and refrigerate overnight! If you don’t want to make this an overnight recipe, simply bake right away!
- Bake the casserole until the top is golden brown and a knife inserted in the center comes out clean. Usually about 50 minutes!!!
How long does Breakfast Casserole last?!
If you’re a smaller household, don’t fret about this going to waste! Because leftovers keep well, stored in the refrigerator, for up to 5 days. You can reheat it in the microwave or oven, or simple eat it cold. Personally, I love making this breakfast casserole on a Sunday night and enjoying a piece for lunch throughout the week. Sometimes I heat it up… but usually I just eat it cold, with lots of hot sauce on top.
Overnight Italian Breakfast Casserole
- 1 Tablespoon olive oil or cooking spray
- 1 pound uncooked Italian sausage, casings removed
- 1 teaspoon Italian seasoning
- 1 teaspoon fresh rosemary, finely chopped
- 1 small onion, diced
- 2 red bell peppers, seeds removed, diced
- 2 cups fresh spinach
- 2 cloves garlic, minced
- 1/2 teaspoon salt
- 1/4 teaspoon black pepper
- 1 dozen large eggs
- 1/2 cup full-fat milk
- 1/3 cup ricotta cheese
- 1/3 cup finely grated Parmesan cheese
- Generously grease a 9×13 casserole dish. Set aside until needed.
- Place a large skillet over medium heat. Add a Tablespoon of olive oil or spray with nonstick cooking spray. Add the sausage to the skillet and, using a spatula, break the sausage up into small chunks. Add in the Italian seasoning and rosemary and continue cooking until the sausage is golden brown and no pink remains. Using a slotted spoon, transfer the sausage to a clean plate and set aside. Discard of remaining grease and return the pan to the burner.
- Add a little more olive oil to the pan. Then add the onions and peppers and cook until they begin to soften, about 6 minutes. Stir in the spinach, garlic, salt, and pepper and continue cooking for another 2 minutes. Add in the sausage and stir to combine. Remove pan from heat and set aside until needed.
- In a large mixing bowl, whisk together the eggs, milk, ricotta, and Parmesan cheese.
- Spread half of the sausage and veggie mixture in the bottom of the prepared casserole dish. Top with the egg mixture, then top with the remaining sausage and veggies. Shake the pan lightly back and forth to gently mix the ingredients.
- Cover casserole and refrigerate overnight, or place the baking dish in the oven and bake at once.
When ready to bake
- Preheat the oven to 35o degreed (F). Bake the casserole, uncovered, for about 55 minutes. Or until it's set in the middle and golden brown. Cool for 10 minutes before slicing and serving.
- Leftovers will keep, wrapped tightly and stored in the refrigerator, for up to 5 days.