Loaded Mashed Potato Casserole

Buttery and creamy mashed potatoes… what’s not to love right? There’s almost nothing more comforting!

How how about if you take those mashed potatoes, stir them up with plenty of cheese, bacon, and green onions, then top them with more cheese and bacon and bake them until gooey and decadent?

Yes please!!! This side dish recipe is such a fantastic one for holidays or a big family dinner, since it serves 8-10 people. It can also be halved or doubled easily, so you can make it exactly as you need it!

Plus, this mashed potato bake is perfect for making ahead of time, so you have less going on during dinner.

How to make loaded mashed potato casserole?

This is just an overview; the full ingredients and directions are in the recipe card toward the bottom of this post.

1. Boil potatoes. There’s no specific amount of water needed, just enough to cover the pot full of potatoes by about 1 inch.
2. Drain and mash. You only need to get the mashing started, then it’ll get mashed more in the next step.
3. Add dairy and mash. The dairy will incorporate much easier if they’re at room temperature, or warmed.
4. Stir in and season. You’ll be stirring in most of the cheese, bacon and green onions.
5. Add to baking dish. You can grease the pan with butter or nonstick spray.
6. Top with remaining cheese and bacon.
7. Bake. After baking, top with the remaining green onions.

Variations of this recipe

• Pre-made mashed potatoes – in a pinch, you can use some pre-made mashed potatoes, or leftover mashed potatoes. Just stir in the amount of cheese, bacon, and green onions that are listed, top with the cheese and bacon amounts listed, bake as directed, and top with the green onion amount listed.
• Garlic – if you want more garlic flavor, feel free to add more cloves of garlic or add a sprinkle of garlic powder when mashing. Conversely, if you don’t want any garlic flavor, you can omit the garlic cloves.
• Dairy amounts – this recipe uses sour cream, heavy cream, and cream cheese, which is what makes the potatoes so incredibly creamy! But please feel free to play around with the amounts of those ingredients (more sour cream and less cream cheese, etc.). Just don’t add more of something without using less of another dairy, otherwise you’ll have overly wet mashed potatoes.
• Smaller batch – this makes a full 9×13″ baking dish full of potatoes, so unless you’re feeding a crowd or want to have plenty of leftovers, you may want to make less. You can halve all the ingredients, then bake in an 8×8″ baking dish instead.
• Add-ins – you can jazz up this mashed potato bake by adding some jalapeños, caramelized onions, roasted garlic, or fried onions (such as French’s brand).
• Other cheeses – feel free to use your favorite cheese for this recipe! We love a great mild or sharp cheddar, but Colby, Colby jack, Gruyere, Pepper jack, etc are all great options. Mix and match for even more flavor!

Making mashed potato casserole ahead of time

Since this can be a time consuming side dish to make all at one time, I recommend making it, or parts of it at least, ahead of time!

Make the mashed potatoes, then stir in the cheese, bacon, and green onions (paying attention to the listed amounts in the recipe that are stirred in, as opposed to being sprinkled on top).

Add to a baking dish, let cool, then cover tightly and refrigerate for 1-2 days.

When ready to serve, let the baking dish sit out at room temperature for about 30 minutes or so to take some of the chill off, then bake as directed, adding some additional time (if necessary) since the baking dish may still be cold.

Storage

Leftover potatoes should be refrigerated in an airtight container and enjoyed within 4-5 days.

This recipe has been on the website since March of 2015, and has been updated in 2022 with new photos, and a few changes to make the recipe even better!