Loaded Mashed Potato Casserole is the most delicious way to repurpose up to 4 cups of leftover mashed potatoes. It’s loaded with bacon, cheese, sour cream and two kinds of onion, and topped with cheese crackers for good measure.

A gold spoon digging into loaded mashed potato casserole in a white baking dish.

Ever wonder what to make with Leftover Mashed Potatoes? Here is the answer!

Thanksgiving is one of my favorite holidays, but with a gathering of just five people, we’re often stuck with quite a bit of leftovers after the big meal.

While you can simply reheat leftover mashed potatoes and drizzle them with gravy from scratch a second time around, my favorite way to serve leftover mashed potatoes is this Loaded Mashed Potato Casserole.

Make this, and you’ll use up 4 cups of mashed potatoes, so this might be the only leftover recipe you need (or, you can easily make a half batch of this if you have less leftovers).

It’s loaded with all the good stuff, like bacon, cheese, sour cream and two kinds of onions, and topped with crushed cheese crackers for good measure.

“This recipe is a winner! Easy to improvise if needed. I made it yesterday and it turned out to be melt in your mouth, delicious and memorable. Absolutely perfect way to use up leftovers!”


Why you will love this Leftover Mashed Potatoes Recipe

  • Revive leftover mashed potatoes (that tend to get a bit dry) by adding lots of moisture and flavor!
  • This casserole is very adaptable to your family’s preferences and whatever ingredients you happen to have on hand. Omit the bacon for a vegetarian dish, or use different herbs, cheese, etc.
  • Delicious enough to take to a Friendsgiving get-together!
The ingredients needed for a leftover mashed potatoes recipe laid out on a light surface, including bacon, onions, sour cream, butter, cheese, herbs, crackers and mashed potatoes.

Mashed Potato Casserole ingredients

  • mashed potatoes – use whatever type of mashed potatoes you have on hand for this leftover mashed potato recipe. I usually make a double batch of mashed potatoes with heavy whipping cream for Thanksgiving, and use the leftovers here.
  • sour cream – this adds some moisture back into the mashed potatoes, which tend to dry out when they’re heated up a second time.
  • garlic powder – I normally use fresh garlic for just about everything, but I actually love the flavor of garlic powder in mashed potatoes!
  • sharp cheddar cheese – because it’s not a loaded mashed potatoes recipe unless we add cheese! You can use any type of cheese you want.
  • bacon – make a quick batch of bacon in the oven and crumble it up. Or, if turkey bacon is more your speed, check out my tutorials on how to cook turkey bacon in oven and turkey bacon in the air fryer!
  • red onion – I add quite a bit of onion to this loaded mashed potato casserole for added flavor. You can also use white or yellow onion.
  • green onion – yes, a second type of onion! I like to add these for color.
  • parsley – this is mainly for color, but you can skip it if you don’t have any on hand.
  • cheese crackers – I love adding crushed cheese crackers (like Cheez-Its or Goldfish) to the top of these baked loaded mashed potatoes for a bit of crunch. You can also use Ritz crackers or potato chips!
  • butter – tossing the crackers in a bit of melted butter ensures they’ll get nice and golden brown on top of the casserole.

“This is KILLER GOOD!! Took to a football party as a side. I felt bad… my dish went before the main one and other sides!!!”

A gold fork lifting up a scoop of mashed potato casserole, with a melted cheddar cheese pull coming out.

What are the top 3 potatoes for mashed potatoes?

For ideal taste and texture, the best potatoes for mashed potatoes are Russet (my top choice), Idaho or Yukon Gold potatoes. The creamy and starchy consistency of these types of potatoes makes the smoothest, most velvety mashed potatoes.

How to make Loaded Mashed Potato Casserole

1. PREP. Preheat the oven, spray a casserole dish with nonstick spray, and stir together the cheese crackers and melted butter to make the topping.

A glass mixing bowl filled with whipped spuds, sour cream, garlic powder and black pepper.

2. WARM AND MIX POTATOES. If your mashed potatoes are cold, microwave them briefly until they are just soft enough to stir again. Stir the sour cream, garlic powder and pepper into the mashed potatoes.

A glass mixing bowl filled with a creamy white mixture on the bottom, topped with bacon, onions, herbs, and shredded cheese.

3. ADD THE MIX INS. Set aside 2 tablespoons each of bacon and cheese, then add the rest of the bacon and cheese, along with the red onion, green onion and parsley to the potatoes. Stir until everything is well combined.

A white rectangle baking dish filled with a light colored casserole mixture.

4. CASSEROLE DISH. Transfer the potato mixture to the prepared baking dish and spread it into an even layer.

A white rectangle baking dish filled with a light colored casserole mixture topped with shredded cheese and bacon.

5. TOPPINGS. Sprinkle the potato mixture with the cracker mixture and the reserved bacon and cheese.

A white rectangle baking dish filled with a light colored casserole mixture topped with shredded cheese and bacon, after baking

6. BAKE. Transfer the dish to the oven and bake 25 to 30 minutes or until everything is heated through.

A loaded mashed potatoes recipe made with bacon, onions and cheese in a white casserole dish.

How to serve Baked Loaded Mashed Potatoes

Serve this luscious casserole as a satisfying side dish to a main course any time of the year, or serve it alongside leftovers of your holiday entree. Some ideas include:

Home Chef Tips for Baked Loaded Mashed Potatoes

  • This recipe works great with leftover mashed potatoes, but you can also make it starting with fresh mashed potatoes (make mashed potatoes specifically in order to make this recipe).
  • If using leftover mashed potatoes, the potatoes do need to be slightly warmed (use the microwave) before stirring in the other ingredients. Cold mashed potatoes are very hard to stir and incorporate with the other ingredients.
A leftover mashed potatoes casserole with bacon, cheese and onions.

Leftover Mashed Potatoes Recipe storage

If you make this mashed potato casserole with freshly-made mashed potatoes, you can cool any leftovers and then store them in an airtight container in the fridge for up to 3 days, or the freezer for up to 3 months.

However, if you make these loaded mashed potatoes using leftover mashed potatoes, I do NOT advise keeping them and reheating them again. 

As a general rule of thumb for food safety, you only want to reheat leftovers once. Anything left over after that, you should discard.

How to reheat mashed potatoes

The easiest way to reheat leftover, plain mashed potatoes is to simply spread them in a buttered casserole dish, cover them with foil, and bake at 350 degrees F until they are completely heated through.

But why not add some extra flavor before you reheat? That’s where this loaded mashed potato casserole recipe comes in, allowing you to add a bunch of flavorful mix-ins before you reheat.

A gold spoon lifting a scoop of baked loaded mashed potatoes out of a baking dish.

Loaded Mashed Potatoes Recipe FAQs

Is it better to bake potatoes for mashed potatoes?

Some people believe that baking potatoes enhances their natural sweetness and gives mashed potatoes a richer flavor profile, but I’ve always made them with boiling water on the stove, and they turn out delicious.

Why add butter before milk in mashed potatoes?

Incorporating butter first would coat the starch molecules of the potato, preventing them from absorbing too much liquid. But, I’ve found that if you use the correct ratio of potato to dairy, this isn’t necessary. I add it all at one time, and again, they turn out delicious!

A gold spoon digging into a mashed potato casserole made with cheese and bacon.
A gold spoon digging into loaded mashed potato casserole in a white baking dish.

Baked Loaded Mashed Potatoes

Yield: 6 servings
Prep Time: 20 minutes
Cook Time: 25 minutes
Total Time: 45 minutes

Loaded Mashed Potato Casserole is the most delicious way to repurpose up to 4 cups of leftover mashed potatoes. It's loaded with bacon, cheese, sour cream, two kinds of onion, and topped with cheese crackers for good measure.


  • Nonstick cooking spray
  • 1/2 cup coarsely crushed cheese crackers
  • 2 tablespoons unsalted butter, melted
  • 4 cups mashed potatoes
  • 1/2 cup sour cream
  • 1/2 teaspoon garlic powder
  • 1/2 teaspoon ground black pepper
  • 6 slices oven baked bacon, crumbled
  • 8 ounces shredded sharp cheddar cheese
  • 1/2 cup finely chopped red onion
  • 3 tablespoons thinly sliced green onion or chives
  • 2 tablespoons chopped fresh parsley


  1. Preheat oven to 350 degrees F. Spray large casserole dish with nonstick spray. In small bowl, stir crackers and butter until well combined.
  2. If mashed potatoes are cold, place in a large microwave-safe bowl and microwave 60 to 90 seconds to soften. Add sour cream, garlic powder and pepper to potatoes; stir until well combined.
  3. Reserve 2 tablespoons each bacon and cheese. Add remaining bacon and cheese to potatoes, along with red onion, green onion and parsley; stir until well combined.
  4. Transfer mixture to prepared casserole dish and sprinkle with cracker mixture and reserved bacon and cheese. Bake 25 to 30 minutes or until heated through.


Home Chef Tip: Casserole can be assembled up to 2 days before baking. Wrap tightly and refrigerate after assembly. To bake, uncover and allow casserole to come to room temperature for 30 minutes before baking as directed (you may need to add a few minutes to the baking time).

Recommended Products

Foxes Love Lemons, LLC is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and links to Amazon.com. There is no additional cost to you.

Nutrition Information:
Yield: 6 Serving Size: 1
Amount Per Serving: Calories: 477Total Fat: 32gSaturated Fat: 14gTrans Fat: 1gUnsaturated Fat: 13gCholesterol: 72mgSodium: 966mgCarbohydrates: 31gFiber: 3gSugar: 4gProtein: 17g

This website provides estimated nutrition information as a courtesy only. You should calculate the nutritional information with the actual ingredients used in your recipe using your preferred nutrition calculator.

Did you make this recipe?

Please let me know what you think! Rate the recipe above, leave a comment below, and/or share a photo to Instagram using the tag #foxeslovelemons.