Cheesy Baked Mashed Potatoes

updated Oct 7, 2022
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Cheesy Baked Mashed Potatoes Recipe

These creamy baked mashed potatoes are loaded with two kinds of cheese and are make-ahead-friendly.

Serves6 to 8

Prep10 minutes

Cook30 minutes to 35 minutes

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Credit: Joe Lingeman

I married into a family that believes pretty much everything is made better with cheese. I can’t say I blame them, because these potatoes are so decadent and showstopping that I’m not sure I’ll ever be able to go back to the original.

What’s more is that these mashed potatoes are the ideal make-ahead side dish. While classic stovetop mashed potatoes are best made right before serving to keep them from drying out, you can make this casserole a full day in advance without having to worry they’ll see the same fate.

Toss it in the oven about 20 minutes before sitting down for Thanksgiving dinner, and you’ll have piping hot mashed potatoes with a golden-brown crust and a rich, creamy, extra-cheesy center to bring to the table.

Credit: Joe Lingeman

What’s the Best Cheese for Cheesy Baked Mashed Potatoes?

I like to use a combination of sharp cheddar, which melts wonderfully, and Parmesan, which adds its signature salty, nutty flavor. But feel free to swap in what you’ve got: fontina or Gruyère can be used in place of Cheddar, while Pecorino is a great substitute for Parmesan.

Sour Cream Is the Secret to the Best Make-Ahead Mashed Potatoes

While it’s the generous handfuls of cheese that make these mashed potatoes truly special, sour cream turns them into the ideal make-ahead side. Using it in combination with the usual butter and milk when mashing coats the potatoes with an extra layer of fat, which protects them from drying out both in the oven and if holding the casserole overnight in the fridge before baking.

The sour cream also lends its signature tang to the potatoes, which offsets the richness of the butter and cheese, making it nearly impossible not to go in for another bite.

More Ways to Enjoy Mashed Potatoes

Because my love for mashed potatoes knows no limits.

Cheesy Baked Mashed Potatoes Recipe

These creamy baked mashed potatoes are loaded with two kinds of cheese and are make-ahead-friendly.

Prep time 10 minutes

Cook time 30 minutes to 35 minutes

Serves 6 to 8

Nutritional Info

Ingredients

  • Butter or cooking spray, for the baking dish

  • 3 pounds

    Yukon gold potatoes (about 8 medium)

  • 3/4 cup

    whole milk

  • 4 tablespoons

    unsalted butter

  • 1 teaspoon

    kosher salt, plus more as needed

  • 1/4 teaspoon

    freshly ground black pepper

  • 1 cup

    sour cream (8 ounces)

  • 8 ounces

    sharp cheddar cheese, shredded (about 2 cups)

  • 1 ounce

    Parmesan cheese, finely grated (about 1/2 firmly packed cup grated or 1/3 cup store-bought)

  • Finely chopped fresh chives or parsley, for garnish (optional)

Instructions

  1. Arrange a rack in the top third of the oven and heat the oven to 400°F. Coat an 8x8-inch or other 2-quart baking dish with butter or cooking spray.

  2. Peel and chop 3 pounds Yukon gold potatoes into 1-inch pieces. Place in a large pot and add enough water to cover the potatoes by 2 inches. Bring to a boil over high heat. Reduce the heat to maintain a simmer and cook until the potatoes are tender and can be easily poked with a paring knife, 7 to 10 minutes. Meanwhile, make the milk mixture and grate the cheeses.

  3. Place 3/4 cup whole milk, 4 tablespoons unsalted butter, 1 teaspoon kosher salt, and 1/4 teaspoon black pepper in a medium saucepan over medium heat. Gently warm, whisking constantly, until the butter is melted, about 3 minutes. Remove from the heat and whisk in 1 cup sour cream.

  4. Shred 8 ounces sharp cheddar cheese (about 2 cups). Finely grate 1 ounce Parmesan cheese (about 1/2 packed cup).

  5. When the potatoes are ready, drain through a heatproof colander and place the colander over the pot. When the potatoes are cool enough to handle but still warm, return to the pot, and mash with a potato masher until mostly smooth (a few lumps are fine). (Alternatively, pass the potatoes through a ricer or food mill back into the pot.)

  6. Pour the milk mixture over the potatoes and stir to combine. Add the shredded cheddar cheese and stir to just combine (the cheese won’t be completely melted). Taste and season with more kosher salt and black pepper as needed. Transfer the mashed potatoes to the prepared baking dish and spread into an even layer. Sprinkle with the Parmesan.

  7. Bake until warmed through, about 20 minutes. Switch the oven to broil and broil until the top in golden-brown, 2 to 3 minutes more. Garnish with finely chopped chives or parsley, if desired, and serve.

Recipe Notes

Make ahead: This casserole can be assembled in the baking dish and refrigerated up to 1 day ahead. Let sit at room temperature for at least 30 minutes before baking.

Storage: Leftovers can be refrigerated in an airtight container for up to 4 days.