Overnight Breakfast Casserole with Bacon and Sweet Potato

Overnight breakfast casserole with bacon and sweet potato is a healthy, hearty breakfast for a crowd! Assemble it the night before, refrigerate, then bake it up in the morning. Gluten-free and lower in carbs.

I don't know about you, but when it comes to holiday breakfasts, I try to get as much done the night before as possible. Overnight French toast casserole and egg-based breakfast casseroles like this one are my jam!

This overnight breakfast casserole has a southwestern flavor twist with sweet potatoes, bell peppers, jalapeno peppers, chili powder and cumin. It feeds a crowd and is easy to make the night before!

Recipe video

Watch the video below to see how simple it is to prep. It’s so easy! You can find more of my recipe videos on my YouTube channel.

Don't forget to pin this post to save it for later!

The formula

This is a really flexible recipe for an overnight breakfast casserole, and you can mix and match it to get your perfect flavor combination!

• the eggs- this part is not flexible; you will need 12 large eggs
• the protein- we are using chopped bacon to infuse the casserole with delicious, salty bacon flavor throughout. Swap with crumbled sausage, cubed ham, or leave it out to make a vegetarian option
• the vegetables- for this southwestern breakfast casserole, we've used bell peppers and jalapeno peppers, but feel free to add in your favorite vegetables: red onions, finely chopped broccoli, zucchini, tomatoes, spinach, asparagus, mushrooms and cauliflower rice would all be great; important- if you add mushrooms, zucchini or any other high water content vegetables, take the time to sautée them before assembling the casserole
• the carbs- many breakfast casseroles use hash browns or bread cubes; I've swapped them for shredded sweet potatoes! You do not need to cook the sweet potatoes before adding them, and they add a nice flavor dimension to the casserole. Swap with an equal volume of hash browns, or 4-6 slices day old bread (torn into 1 inch cubes)
• the seasonings- this recipe adds chili powder and ground cumin to give it a Southwestern flavor; feel free to omit them, or add in some other spices: dried oregano and basil could give it a mediterranean feel
• the cheese- I've used regular old cheddar cheese for this recipe; pepper jack or jalapeno infused cheese could have been even better! Consider using mozzarella, feta or even goat cheese to change things up.

How to make it the night before

Prepping this breakfast casserole the night before makes it so hands off the next morning, which leaves you free to hang out with your guests rather than being stuck in the kitchen!

1. prep the fillings- Cook the bacon (consider baking it in the oven!). Cool, then chop it up. Dice the bell peppers and jalapenos, and shred the sweet potatoes on a box grater. Shred the cheese
2. assemble the casserole- You'll need a deep casserole dish to fit this recipe (I use this one from Crate & Barrel). Grease it with spray oil or butter, spread the sweet potatoes and bell peppers, bacon, and part of the cheese. Beat the eggs with milk, salt, chili powder and cumin, then pour evenly over the filling. Scatter remaining cheese over top.
3. cover and refrigerate- Use plastic wrap or a reusable silicone lid to cover the dish, and place in the fridge overnight. This overnight step is not essential, and if you'd like, you can bake it up immediately.
4. bake the casserole- Remove the casserole from the fridge and allow to stand at room temperature while the oven pre-heats. Remove the cover or plastic wrap and bake at 375°F for 45 minutes to 1 hour.
5. enjoy- serve with salsa, fresh tomatoes, or avocado!

Recipe tips

Bake right away OR make it ahead

While this is called an overnight breakfast casserole, you are also welcome to bake it up right away! Simply place it in the oven (uncovered), and cook for 45 minutes- 1 hour. There is no flavor benefit to making it the night before, it simply makes the morning less stressful.

How to tell when it's done

When baked through, the center of the casserole puffs up and becomes more firm. If you are wondering if your casserole is cooked through, first give it a little shake. If it is jiggling and not set, it is likely not ready. You can also insert a knife into the middle of the casserole to see if wet egg sticks to it.

Finally, you can test the internal temperature of your casserole by using an instant read thermometer. Egg-based recipes should reach a temperature of 160°F in the middle section.

Let it sit 10 minutes

While it might be tempting to dig right into the fresh-from-the-oven casserole, it will be quite soft and prone to crumbling. Allowing your casserole to cool for 10 minutes will help things set up, making it easier to serve up.

Storage, freezing and reheating

This is such a flexible recipe that holds up in the fridge as well as the freezer. Note that the casserole will be slightly 'wetter' after storing, and reheating in the oven can help evaporate off some of the liquid.

Storing in the fridge

Cool the casserole completely, before covering or portioning out into individual portions. Store covered (or in an air tight container) for up to 4 days in the fridge.

Freezing it

Cool the casserole completely before freezing.

• Whole casserole- Cool completely, then cover with plastic wrap and foil. Freeze up to 3 months.
• Individual portions- After baking, cool and portion out the breakfast casserole. Wrap with plastic wrap and store in a large freezer bag or individual container.

Thawing and reheating

Thaw whole casserole or individual portions overnight in the fridge. I find that microwaving eggs from frozen can make them rubbery, but it is possible to do.

Reheat individual portions in the microwave (they will be slightly wetter, you can use a paper towel to wick away any extra moisture).

Reheat the whole casserole uncovered in the oven at 350°F for 30-40 minutes or until warmed through in the center.

More breakfast ideas

• Crockpot Breakfast Casserole
• Baked Oatmeal Recipe
• 36 Healthy Breakfast Meal Prep Ideas
• Crispy Overnight Yeast Waffles
• Blueberry Baked Oatmeal
• Herb & Zucchini Egg Bake
• Crockpot French Toast Casserole