Cheesy Mashed Potato Casserole

plate with a scoop of cheese mashed potato casserole.

5 from 22 votes

This Cheesy Mashed Potato Casserole combines the classic mashed potatoes that are packed with flavor and melted cheese. It's the ultimate side dish for your Sunday dinners.

Prep Time15

Cook Time20

Total Time35

Course: Side Dish

Cuisine: American

Servings: Servings

Calories: 615kcal

Author: Wendy

Equipment

9x13 casserole dish
Large Mixing Bowl

Ingredients

10 cups prepared mashed potatoes
¼ cup unsalted butter melted
1 cup sour cream
1 teaspoon garlic powder
Salt and pepper to taste
1 ½ cups shredded cheddar cheese divided
¼ cup chopped fresh chives or green onions optional, for garnish

Instructions

Preheat your oven to 350°F (175°C) and grease a large baking dish (9x13-inch or similar size).
In a large bowl, combine the mashed potatoes and melted butter.
Stir in the sour cream. If the consistency seems too thick, you can stir in milk a little at a time until your desired consistency is reached.
Season the mashed potatoes with garlic powder, salt, and pepper to taste. Adjust the seasoning according to your preference. Fold in 1 cup of shredded cheddar cheese until it's evenly distributed throughout the mixture.
Spread the creamy mashed potatoes evenly in the greased baking dish. Sprinkle the remaining 1/2 cup of shredded cheddar cheese over the top of the mashed potatoes.
Place the casserole in the preheated oven and bake for about 20-25 minutes, or until the cheese is melted and bubbly and the edges of the casserole are slightly golden.
Remove the casserole from the oven and let it rest for a few minutes. Garnish with chopped chives or green onions, if desired.

Notes

I've found that russet potatoes will give you the best texture when you are making a casserole dish like this.
You can also use Yukon gold potatoes for a more buttery flavor. I used homemade mashed potatoes, however, you can save time and use pre-made mashed potatoes that you purchased at the store.
The kind in the refrigerated section would work well.
A glass or ceramic casserole dish will give you the best results when making this casserole. A metal dish may cause the bottom of your mashed potatoes to burn.

Any nutritional data I provide is an approximation and actual dietary information can vary based on ingredients and proportion sizes.

Nutrition