With just a few minutes of prep, this mashed potato casserole recipe comes out super creamy and cheesy. These baked mashed potatoes are the perfect side dish and a great way to use up leftovers. And best of all? You can prep them ahead of time!
Mashed potatoes are a staple on any family dinner table, especially for larger get-togethers. However, there's not always time between dishes to whip them up. This is what makes this mashed potato casserole recipe so perfect.
Just make it in advance and heat it when you need it. This simple but flavorful side dish tastes just as delicious the next day as it does freshly made, and is an easy way to wow your guests.
Why you will love this recipe
- Easy to make with just six ingredients
- Quick prep - just a few minutes once the potatoes are cooked
- Use up leftovers: This recipe is a tasty way to use up and repurpose leftover mashed potatoes so that nothing goes to waste
- Lots of cheesy flavor: Everyone loves a cheesy potato side dish and this mashed potato casserole recipe will be no different
- Use any mashed potatoes you like, but I recommend making it with cheesy mashed potatoes or mashed potatoes without milk
- Easy to prep or make ahead, so it's perfect for Holiday dinners where it can be prepped up to 24 hours in advance
What you need to make it
Ingredient notes & substitutions
- Mashed potatoes: If you already have leftovers, or a recipe you love to use - great! If not, there's a recipe included below for Cheesy Mashed Potatoes.
- Potatoes: Any potatoes will work, though we use Yukon gold potatoes or russets the most for mashed potatoes. To cook them quicker, cut them into smaller pieces before boiling.
- Butter: Salted and unsalted both work equally well
- Cream cheese: Make sure to use full-fat cream cheese for the richest flavor
- Parmesan cheese can be swapped for another flavorful, well-melting cheese like Gruyere, or any other kind you enjoy
- Shredded cheese: Shred it yourself for best results. If using the store-bought kind, make sure it's 100% cheese with no additives added, as these can make the end result come out grainy.
- Seasonings: all you need are salt and pepper for this make-ahead mashed potato casserole. Taste test the mashed potatoes before seasoning!
How to make it
- Make the mashed potatoes, or bring out your leftovers. Spread out in a n oven-safe dish and even out the surface.
- Top with shredded cheese
- Bake until the top is golden brown, and let it rest a few minutes before serving
Tips & tricks
- Keep an eye on it in the oven. If the top starts to brown too much, cover it with aluminum foil so that it doesn't burn.
- If it doesn't get enough color - raise the heat for the final 5-10 minutes
- Use your favorite cheeses: A flavorful one in the mashed potatoes and a well-melting kind (like mozzarella) on top.
- Use your leftovers: This recipe is great to use up leftover mashed potatoes. Just heat them slightly in the microwave and mix in the cheese and seasonings from there.
Fun Flavor Options
Bacon: Top this casserole with chopped bacon for added savory flavor and crunch.
Garlic: If you love a garlic mash, either use a bit of garlic powder along with the salt and pepper or mince your garlic and stir it in while mashing. For a subtle flavor you can also just add a few crushed garlic cloves with the potatoes while boiling. Remove them before mashing.
Cheese: Any of your favorite cheeses will work. Topping it with cheddar cheese or even Swiss can be a fun swap.
Loaded potatoes: When you serve the mashed potato casserole, sprinkle on (or set out on the table) some green onions, bacon bits, chives, and sour cream.
Storing, Freezing, Reheating & Making Ahead
Storing: Store leftovers of this mashed potato casserole recipe in an airtight container in the fridge. It will be good for up to 4 days.
Freezing: Place them in a freezer-safe bag or container. When you're ready to eat them, let the potatoes thaw in the fridge overnight.
Make ahead: prepare the mashed potato bake all the way, but don't bake it. Keep it covered in the fridge for up to 24 hours. When you need it, bake it in the oven for 20-30 minutes before serving.
More quick & easy potato sides
Looking for more quick & easy side dishes to try?
- Leftover Boiled Potato Casserole
- Air Fryer Potato Skins
- Leftover French Fries Casserole
- Air Fryer Baked Potatoes
- Air Fryer Baby Potatoes
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Mashed Potato CasserolePrint Rate
Cheesy Mashed Potatoes
- 2 lb potatoes peeled and cut in smaller pieces
- 1 tablespoon salt for seasoning potato boiling water
- ¼ cup butter salted or unsalted
- 1 cup cream cheese
- 1 cup shredded Parmesan cheese or other flavorful cheese like Gruyere
- ½ teaspoon fine table salt or according to taste
- ½ teaspoon ground black pepper or according to taste
Mashed Potato Casserole
- ½ cup shredded cheese a well melting kind like mozzarella
- To start, boil the potatoes in a large pot with salted water until tender, then drain them.2 lb potatoes, 1 tablespoon salt
- Preheat oven to 430℉ (220℃).
- Mash the potatoes while still hot, then add butter in pieces. Mash together until butter is melted and mixed in with the potatoes.¼ cup butter
- Add cream cheese and mix until well incorporated.1 cup cream cheese
- Fold in shredded Parmesan cheese, then taste test and season with salt and pepper as needed.1 cup shredded Parmesan cheese, ½ teaspoon fine table salt, ½ teaspoon ground black pepper
- Transfer mashed potatoes to an oven safe baking dish, and even out the surface. Top with shredded cheese.½ cup shredded cheese
- Bake in the middle of the oven at 430℉ (220℃) for 25-30 minutes. If the top starts to brown too much, cover with aluminium foil. It's done when well heated through and the top is melted and golden brown. Let it rest a few minutes before serving.
Equipment (may contain affiliate links)
- Oven safe dish 1.5 quarts, round: 8 inches (20 cm) across, rectangular: 10 x 7 inches (25 x 18 cm). 2-3 inches / 5-7.5 cm high.
- Measuring cups
Nutritional information is approximate and automatically calculated, and should only be viewed as an indication.