This Overnight Breakfast Casserole is the PERFECT set-it-and-forget-it kind of breakfast! It's simply Onederful! No, that isn't a typo. You'll see why I really should have named this recipe Onederful Breakfast Casserole in just a bit! 

I kid you not when I say you can whip this up in 10 minutes flat and let the Ninja Foodi Slow Cooker take it from there. Isn't that Onederful? 

I love making breakfast, but I don't love starting my day off with tons of dishes or spending an hour making breakfast; especially when we have overnight guests!

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Who wants to be spending time in the kitchen while your guests are relaxing and chatting over coffee? Not me. This Overnight Breakfast Casserole is simply perfect for a hearty breakfast and definitely serves a crowd! Isn't that Onederful? 

If you are wondering why I keep saying Onederful instead of wonderful, here is why! 

Onederful Overnight Breakfast Casserole Ingredients

Overnight Breakfast Casserole is so simple to make and all you have to remember is Onederful!

You will need: 

• One dozen eggs
• One pound of ham
• One pound of potatoes
• One onion
• One cup of heavy whipping cream
• One bag of cheese (16 oz)
• Butter (ugh... why didn't I just use 1 tablespoon instead of 2!) 

See... Onderful! Except for one thing... the butter. I added two Tablespoons of butter. I could have certainly taken that down to One Tablespoon, but it was so good... I left the recipe as is. I still think we can call it Onederful though! 

Can I use different Ingredients in the Overnight Breakfast Casserole? 

Of course and I encourage you to do just that! The first time I made it with sausage and I thought that was going to be great. Yeah... well, it kind of wasn't. It was boring. I'm certainly not saying that you can't make it Onederful with sausage, but you might want to add some spices and get a really flavorful sausage. 

Sausage instead of Ham: You want to make sure to cook your sausage and drain the grease (or use the grease insead of the butter) before adding to the overnight breakfast casserole and I also recommend adding some salt, pepper and other seasonings you like to jazz it up a bit. 

Bacon instead of Ham: Personally, I wouldn't recommend this because even if you crisp up your bacon before adding, in the 8 hours of slow cooking it is going to get very soft. If you don't mind this, or even like your bacon this way, then by all means go for it! The taste will be great I'm sure! 

Go Mexican: I just thought of this one and it sounds so good, I'm going to try it out when Jeff's parents come to visit. I would use ground beef, taco seasoning of choice, 1 cup of salsa instead of the heavy cream, and mexican cheese. You could even add in some Chorizo for good measure! If you want a great, yet simple, Mexican seasoning blend, check out my recipe for Mexican Pot Roast! 

Vegetarian Style: This would be a great vegetarian breakfast. Just add in a couple of cups of the vegetables you like. I would decrease the heavy cream to ½ cup to allow for the added moisture from the veggies. 

Low Carb: Lose the potatoes and load it up with meat and cheese. 

The possibilities are endless, so switch up those ingredients and make exactly the overnight breakfast casserole you love!

How does the slow cooker work on the Ninja Foodi? 

If you are in any Facebook groups, you probably have seen where people say the slow cooker doesn't work that well on the Ninja Foodi. This really surprises me when I see these comments because I LOVE the slow cooker function! I think it works exactly like it should. 

I never slow cooked much because I always thought the food overcooked and I used my crock pots mostly for hauling food to parties and keeping things warm when I entertained at home. I still have mine, so I decided I'd do a little experiment for you. 

This is how I set it up -- and keep in mind, this is not a scientific experiment with controls and such, it's just a simple test to see how the Ninja Foodi measures up to the Hamilton Beach slow cooker.

I put 2 cups of cool tap water into the inner pots of the Ninja Foodi and the Hamilton Beach slow cooker. First, I set the temp to the low setting for both appliances and tested the water temperature with a food thermometer every 30 minutes for 3 ½ hours. 

I used a thermometer that gives a pretty quick reading and has been very accurate based on other testing I've done. If you are in the market for a good thermometer, but don't want to spend an arm and a leg for one, you can find the one I used right here: ThermaPro TP-18

The second test I put 2 cups of cool tap water into the inner pots of both appliances and set the temp to the high setting. I tested the water temps every 30 minutes for 3 ½ hours. 

Here are the results.

As you can see, the Hamilton Beach slow cooker did heat up faster and maintained a higher temp all throughout the cooking time on the low setting. 

My opinion on this is in the next section. 

What I found very interesting is how the Hamilton Beach slow cooker started off cooking at a higher temp while on the high setting, but towards the end it dropped below the temp of the Ninja Foodi. 

I have some ideas on why this happened and I'll explain more in the next section. 

My opinion on the results of the slow cooker experiment

While at first glance, you may think that the Hamilton Beach slow cooker does a better job than the Ninja Foodi slow cooker function, but I don't agree. 

The reason we slow cook food is to be able to set it and forget it, right? We want our slow cooked meal to be fully cooked over a slow period of time. We expect our meats to be juicy and tender, our veggies cooked perfectly, and our soups full of flavor. 

For these reasons, I think the Ninja Foodi slow cooker function works perfectly! Before I get into that, let's talk about safety while slow cooking. 

Food Safety when Slow Cooking

When slow cooking, it is important that the food you are cooking gets up to 140° F within a 4 hour period of time. This is the temperature at which bacteria growth is slowed or inhibited. You can see more on this in this CHART. 

Both appliances did fine with this and, even though I was only testing water, I don't think there is anything to be concerned about when cooking food in either appliance. I plan on doing some testing with food in both appliances and posting my findings in a separate article. 

It is NOT recommended that you slow cook frozen meats or other foods that will not reach the 140° F within the 4 hour period. For this reason, I think the Foodi wins for sure! If you want to cook something from frozen, simply PC it for several minutes to thaw and then begin the slow cooking process. You can read more on slow cooking safety HERE. 

Why I think the Ninja Foodi is a BETTER slow cooker than my Hamilton Beach slow cooker

I mentioned earlier that I was never a fan of slow cooking and that is because I always felt the slow cooker overcooked my food or cooked meat too fast for it to benefit fully from a low and slow cook. 

Now, I know people will disagree with me on this and that is fine. We are all entitled to our opinions and, as long as it is safe, please use whichever appliance gives you the best result. 

For me, it's the Ninja Foodi. I haven't done a ton of slow cooking in it because I happen to LOVE using the PC function, it is such a time saver! The food I have cooked with the slow cooker function of the Ninja Foodi has turned out better than anytime I made it with my old slow cooker. 

I think it is because the meat is cooked at a lower temp which allows the collagen (tough parts) of meat to break down at a controlled rate resulting in a moister and more tender end result. This is just my opinion and not supported by any research that I have done, simply an observation. 

If you look at the chart above, you will also see that the Hamilton Beach slow cooker started reducing in temp towards the end of the 3 hours. I also noticed that the water level in the Hamilton Beach kept going down while on the high setting, while the Ninja Foodi maintained a constant water level. 

The decreasing water level is the reason those temps went down towards the end of the cooking time on the Hamilton Beach slow cooker. I almost had to forgo a final temp because there was almost no water left. I managed to find a small pool of water to get that last temp without hitting the bottom. 

So, what does that mean? It means there was way more evaporation using the Hamilton Beach slow cooker than the Ninja Foodi slow cooker. How does that affect the food we are cooking? Well, that depends on what is in the pot, but most of the time we aren't slow cooking to reduce moisture, we are slow cooking to preserve it. 

With the high evaporation while using the HB slow cooker, I have a feeling that the same size pot roast would be much drier than one cooked in the Ninja Foodi. I will have to do that experiment soon! I could be wrong, but I look forward to finding out. 

So, my final thoughts are that the Ninja Foodi is the slow cooker for me! I've been impressed with all the functions on the Ninja Foodi and this one did not disappoint either. 

Will this Recipe Work in Another Brand of Slow Cooker? 

I have not tried it, so I really can't answer that. However, based on my findings during the experiment with my Hamilton Beach slow cooker, I think it may overcook in 8 hours. 

Of course this depends on how hot your slow cooker gets. You could try the low setting for a shorter period of time, but even then I'm not sure the texture of the eggs would be the same. High heat is not an eggs best friend.

What happens if let the Overnight Breakfast Casserole cook longer than 8 hours? 

Nothing. The Ninja Foodi will switch to the keep warm function and you can eat anytime you'd like. When I filmed the video for the overnight breakfast casserole, I started it at about 8pm the night before and didn't get to it for almost 12 hours and it was perfect. 

How to Make Overnight Breakfast Casserole in the Ninja Foodi

If you prefer to watch me make this breakfast casserole, you can click right here: Overnight Breakfast Casserole Video

Dice the onion into ½" dice. Turn the Ninja Foodi on High Sear/Sauté. Add butter and onions, sauté for about 5 minutes. While the onions are sautéing, cut up your potatoes into ½" dice and add to the pot. Peel or don't peel, the option is yours. I don't peel mine; there are tons of vitamins in the potato skin. 

TIP: I recommend using Russet potatoes instead of a gold potato or a new potato because they cook more evenly in this dish. Some of my gold potatoes were hard when I tested this recipe using them. 

Crack 12 eggs into a large mixing bowl. Remember when I said you can throw this breakfast casserole together in 10 minutes? It's because you can use an immersion blender to get those eggs whipped up fast as lightning. Okay, not that fast... but seriously, in less than 60 seconds they are done! 

If you aren't familiar with an immersion blender or just haven't gotten around to getting one, I highly recommend picking up one. Not only do they whip up eggs super fast, they do tons of other stuff. If you like to make creamy butternut squash, it's a must have! No more having to dump hot liquid into a regular blender. I love, love, love the one I have because it's super easy to clean and has all the bells and whistles. You can find it Right Here on Amazon: Utalent Immersion Blender

Turn off the Ninja Foodi and dump in the eggs and the heavy cream. Cut the ham into bite size pieces, I made them about 1" cubes. Add the ham and the cheese. Stir to combine. Put the pressure lid on and turn the seal to vent. 

This is important. Make sure the valve is to the vent position when using the slow cooking function of the Ninja Foodi. 

Set the Slow Cooker function to low for 8 hours. Relax. Put your feet up. Watch a movie. Sleep. Enjoy your time because breakfast is now making itself! See the before and after! 

Finishing touches: You can serve the breakfast casserole just as it is or top it with the remaining cup of cheddar cheese and broil for about 5 minutes or until the cheese is browned like you like it. Serve and Enjoy!