Mashed Potato Casserole Recipe

Mashed potato casserole takes everyday mashed potatoes and turns them into a make-ahead side with a golden, crisp top. Cream cheese and sour cream keep the inside soft, while a quick broil at the end adds that toasted layer on top.

It’s a simple way to serve mashed potatoes to a crowd without standing over the stove right before dinner. This version comes together with pantry staples, so it works for both weeknight dinners and bigger holiday spreads.

Ingredients

Servings: 8

• 3 lbs Yukon gold potatoes, peeled and cubed
• 1/2 cup sour cream
• 4 oz cream cheese, softened
• 1/2 cup milk
• 4 tbsp butter, plus more for the dish
• 1 tsp salt, plus more to taste
• 1/2 tsp black pepper
• 1/2 cup shredded cheddar cheese
• 2 tbsp chopped chives, plus more for garnish

Boil the Potatoes

Place the cubed potatoes in a large pot and cover with cold water. Bring to a boil, then lower the heat and simmer for 15 to 18 minutes, until the potatoes are fork-tender. Starting the potatoes in cold water helps them cook evenly all the way through, instead of getting mushy on the outside before the center is done.

Drain and Dry the Potatoes

Drain the potatoes well and return them to the pot. Let them sit over low heat for a minute, shaking the pot gently, to cook off any extra moisture. This step keeps the casserole from turning watery later.

Mash Until Smooth

Add the butter, sour cream, and cream cheese to the hot potatoes. Mash everything together until smooth, using a potato masher or a hand mixer depending on how creamy you want the texture.

Season and Mix In Milk

Pour in the milk a little at a time, stirring until the mash reaches a soft, spreadable texture. Add the salt and pepper, then taste and adjust as needed.

Fold In the Chives

Stir the chopped chives into the mashed potatoes, saving a small handful for garnish later. This adds a mild onion flavor throughout the dish instead of just on top.

Transfer to the Baking Dish

Grease a 9×13 baking dish with butter. Spread the mashed potatoes evenly into the dish, smoothing the top with a spatula so it bakes evenly.

Add the Cheese Topping

Sprinkle the shredded cheddar cheese evenly over the top of the potatoes. This layer melts and browns in the oven, giving the casserole its golden finish.

Bake Until Golden

Bake at 375°F for 25 to 30 minutes, until the edges bubble and the cheese turns golden brown. For extra color on top, switch the oven to broil for the last 2 minutes and watch closely so it doesn’t burn. Ovens vary quite a bit, so start checking a few minutes early the first time you make this.

Rest Before Serving

Let the casserole sit for about 5 minutes after baking. This gives it time to set slightly, so it holds its shape better when you scoop it out.

Garnish and Serve

Top the casserole with the remaining chives right before bringing it to the table. Serve warm alongside your main dish.

How To Make This Mashed Potato Casserole Better

A few changes can push this dish further. Roast a head of garlic and mix the softened cloves into the mash for a deeper, sweeter flavor. Swap half the cheddar for gruyere or parmesan if you want a sharper, nuttier topping. For a smoky twist, mix in some crumbled cooked bacon along with the chives.

If you like a bit of crunch, sprinkle breadcrumbs mixed with melted butter over the cheese before baking.

Can You Make Mashed Potato Casserole Ahead of Time?

Yes, this dish is a good make-ahead option. Assemble the casserole up to the point of baking, then cover and refrigerate for up to two days.

When you’re ready to serve, bake it straight from the fridge, adding about 10 extra minutes to the cook time. This makes it a solid pick for holiday dinners, since it frees up oven space and stovetop time on the day itself.

Can You Freeze Mashed Potato Casserole?

Yes, you can freeze it either before or after baking. Wrap the dish tightly in plastic wrap and foil, then freeze for up to two months.

Thaw it in the fridge overnight before baking, or add extra time in the oven if baking from frozen. If you’re freezing it unbaked, hold off on the cheese topping until you’re ready to bake, since fresh cheese browns better than cheese that’s been frozen and thawed.