Name: Mashed Potato Casserole
Prep time: 20 min
Cook time: 30 min
Total time: 50 min
Cuisine: American
Ingredients: 3 pounds Russet or Yukon Gold potatoes, peeled and cubed; 4 tablespoons unsalted butter; 3/4 cup sour cream; 1/2 cup whole milk (warmed); 1 1/2 cups shredded sharp cheddar cheese, divided; 1 teaspoon garlic powder; Salt and pepper, to taste; 1/4 cup grated Parmesan cheese; 2 tablespoons chopped fresh chives (optional)

Creamy, fluffy mashed potatoes are already a crowd-pleaser, but when you bake them into a bubbly, cheesy casserole, they become the ultimate comfort food. Mashed Potato Casserole is the side dish that turns any meal into a cozy celebration, whether it’s a holiday feast or a weeknight dinner.

This dish layers buttery mashed potatoes with sour cream, sharp cheddar, and a golden, crispy topping. It’s make-ahead friendly, reheats like a dream, and disappears fast once served. Whether you’re hosting guests or just treating yourself, this casserole is always a win.

What Kind of Potatoes Work Best for Mashed Potato Casserole?

For ultra-creamy texture, opt for Russet or Yukon Gold potatoes. Russets are starchy and light, while Yukon Golds are naturally buttery and a bit denser. You can even mix the two for balance. Be sure to drain them well after boiling to avoid watery potatoes.

Ingredients for the Mashed Potato Casserole

3 pounds Russet or Yukon Gold potatoes, peeled and cubed
4 tablespoons unsalted butter
3/4 cup sour cream
1/2 cup whole milk (warmed)
1 1/2 cups shredded sharp cheddar cheese, divided
1 teaspoon garlic powder
Salt and pepper, to taste
1/4 cup grated Parmesan cheese
2 tablespoons chopped fresh chives (optional)

How To Make the Mashed Potato Casserole

Step 1: Boil and Mash the Potatoes

Peel and cube the potatoes, then boil them in salted water until fork-tender, about 15 minutes. Drain well and return them to the pot. Mash until smooth.

Step 2: Mix in the Creamy Goodness

Add the butter, sour cream, warm milk, garlic powder, salt, and pepper. Stir until everything is fully combined and the texture is fluffy and smooth.

Step 3: Add the Cheese

Fold in 1 cup of the cheddar cheese and mix gently.

Step 4: Bake the Casserole

Spread the mashed potatoes into a greased 9×13 baking dish. Top with the remaining cheddar cheese and sprinkle the Parmesan evenly. Bake at 375°F for 25-30 minutes, until bubbly and golden.

Step 5: Garnish and Serve

Top with chopped chives before serving for a fresh pop of flavor and color.

Serving and Storing This Comforting Classic

Serve the Mashed Potato Casserole warm, straight from the oven. It pairs beautifully with roast meats, grilled vegetables, or as a main dish with a simple salad.

To store, let it cool completely and cover tightly. It will keep in the refrigerator for up to 4 days. Reheat in the oven at 350°F until warmed through, or microwave individual portions.

Frequently Asked Questions

Can I make this ahead of time?

Absolutely. Prepare the casserole up to the baking step, cover, and refrigerate. Just add a few extra minutes when baking from cold.

Can I freeze Mashed Potato Casserole?

Yes! Let it cool completely, then freeze in an airtight container for up to 2 months. Thaw overnight in the fridge before reheating.

What can I substitute for sour cream?

Greek yogurt or cream cheese both work well and add tangy richness.

Can I add bacon or other mix-ins?

Definitely. Crumbled cooked bacon, green onions, or even caramelized onions make great additions.

How do I prevent the casserole from getting watery?

Make sure to drain the potatoes thoroughly after boiling, and avoid adding too much liquid.

Want More Casserole Ideas?

If you loved this Mashed Potato Casserole, try some of these other satisfying favorites:

Nutella French Toast Casserole for a sweet breakfast twist.
The Ultimate Taco Casserole Recipe packed with zesty flavors.
Chicken Cordon Bleu Casserole for creamy, cheesy indulgence.
Sour Cream Beef Noodle Casserole with rich, comforting layers.
Easy Tuna Noodle Casserole with Cream Cheese for a pantry-friendly meal.

📌 Save this Mashed Potato Casserole to your Pinterest side dish board for easy access next time you need a guaranteed hit.

And let me know how you made it your own! Did you use extra cheese? Add bacon? I’d love to hear your spin on this classic. Leave a comment and share your tips.

For more cozy recipes and kitchen inspiration, follow along on Pinterest @NinaDishes.

Mashed Potato Casserole

Author: Nina Klatten
Total Time: 50 minutes
Yield: 8 servings
Diet: Vegetarian

Print Recipe

Description

This Mashed Potato Casserole takes creamy mashed potatoes to the next level with sour cream, cheddar cheese, and a crispy, golden topping. It’s the ultimate make-ahead side dish for holidays or cozy weeknights.

Ingredients

3 pounds Russet or Yukon Gold potatoes, peeled and cubed

4 tablespoons unsalted butter

3/4 cup sour cream

1/2 cup whole milk (warmed)

1 1/2 cups shredded sharp cheddar cheese, divided

1 teaspoon garlic powder

Salt and pepper, to taste

1/4 cup grated Parmesan cheese

2 tablespoons chopped fresh chives (optional)

Instructions

1. Peel and cube the potatoes, then boil them in salted water until fork-tender, about 15 minutes. Drain well and return them to the pot. Mash until smooth.

2. Add the butter, sour cream, warm milk, garlic powder, salt, and pepper. Stir until everything is fully combined and the texture is fluffy and smooth.

3. Fold in 1 cup of the cheddar cheese and mix gently.

4. Spread the mashed potatoes into a greased 9×13 baking dish. Top with the remaining cheddar cheese and sprinkle the Parmesan evenly. Bake at 375°F for 25-30 minutes, until bubbly and golden.

5. Top with chopped chives before serving for a fresh pop of flavor and color.