Cheesy Mashed Potato Casserole

A spoonful of loaded mashed potato casserole up over a plate with more.

5 from 3 votes

Cheesy Mashed Potato Casserole

This is by far the BEST Loaded Mashed Potato Casserole! Creamy mashed potatoes combine with sour cream, butter and cheese to make the base of the dish and then add on plenty of toppings. It's the perfect potato casserole for holidays, lazy weekends, or any time you need an easy, yet delicious potato side dish.

Prep Time10

Cook Time30

Boil Time20

Total Time1

Servings:

Calories: 397kcal

Author: Karin and Ken

Ingredients

8-10 russet potatoes
2 tablespoons butter
⅓ cup milk
½ cup sour cream or sour cream based flavored dip
2 ¾ cups cheddar and monterey jack cheeses shredded, divided
1 teaspoon garlic salt
½ teaspoon pepper

Optional Toppings or Mix-ins

2 tablespoons ranch seasoning or ¼ cup ranch dressing and only ¼ cup of milk
chives or green onions
¼ cup parmesan cheese
bacon or bacon bits
diced green chiles or jalapeno
crispy fried onions

Instructions

Preheat your oven to 400 degrees.
Peel and chop potatoes, then boil in salted water until soft, about 15-20 minutes. Drain and return to pot or a large bowl.
Ideally, using a handheld mixer, add butter to your potatoes. I add butter first while the potatoes are hot so the butter melts easily.
Add milk, sour cream, ranch (if using), cheese, garlic salt, pepper and any other option you want to include. Blend ingredients together. TASTE your potatoes and add more of whatever you think they need, if anything at all.
Spray a casserole dish with cooking spray and press your potatoes into it. Try and make the top as even as possible.
First, I sprinkle bacon all over the top (if using), then crispy fried onions, and parmesan cheese (if using). Last, I sprinkle between ½ - 1 cup of shredded cheddar and monterey jack cheeses all over the top. Sometimes a little more, sometimes a little less.
Bake for 25-30 minutes until top is a golden brown. Sometimes I will broil for a minute or two to darken the cheese a little more, if needed.
Top with chives or green onions. Serve as desired.

Video

Notes

Want a Crispy Top. Broil the casserole for just a few minutes at the end of cooking to brown and crisp the cheese.

Additional Ingredients. You can stir bacon, chives, or other ingredient mix-ins into the mashed potato mixture OR add them on top!

Adjust the Quantities: Remember you can add more cheese, less cheese, or really change up any ingredient to make your casserole taste exactly how you love.

Nutrition