Name: Mashed Potato Casserole
Prep time: 20 min
Cook time: 30 min
Total time: 50 min
Cuisine: American
Ingredients: 6 large russet potatoes; 6 tablespoons butter; 1 cup sour cream; 1 cup milk or heavy cream; 1 teaspoon garlic powder; 1 teaspoon salt; 1⁄2 teaspoon black pepper; 1 cup shredded cheddar cheese (optional); 2 tablespoons chopped chives or green onions (for garnish)

Creamy, buttery, and irresistibly smooth, Mashed Potato Casserole takes comfort food to a whole new level. Whether you’re hosting a holiday gathering or need a reliable side for weeknight dinners, this baked twist on classic mashed potatoes delivers rich flavor in every scoop. It holds beautifully for serving, reheats like a dream, and adds an elegant touch to any meal.

Unlike regular mashed potatoes, this casserole is baked until golden and slightly crisp on top, while remaining fluffy and creamy inside. Infused with sour cream, butter, and just the right amount of seasoning, it turns simple ingredients into a showstopping side dish. You can make it ahead, customize it with toppings like cheese or herbs, and pair it with anything from roast turkey to grilled veggies.

Preparation Phase & Tools to Use

To create the perfect Mashed Potato Casserole, having the right tools on hand can make a big difference:

Large Pot: This is where your potatoes get boiled to soft perfection. A heavy-bottomed pot ensures even cooking.
Potato Masher or Ricer: For that ultra-creamy consistency. A ricer gives you smooth, lump-free potatoes, while a masher adds a rustic texture.
Mixing Bowls: You’ll need a large one to mix the mashed potatoes with all the add-ins like butter and sour cream.

Hand Mixer (optional): If you prefer your mashed potatoes extra airy and whipped, this tool helps create a cloud-like texture.
Casserole Dish: A medium to large baking dish allows the potatoes to bake evenly and develop that lightly golden crust on top.
Spatula or Wooden Spoon: Essential for gently folding ingredients together without overworking the potatoes.

Ingredients for the Mashed Potato Casserole

Every ingredient in this recipe plays an essential role in building the rich, velvety texture and indulgent flavor:

Russet Potatoes: The ideal potato for mashing thanks to their starchy texture. They become fluffy and smooth when boiled and mashed.
Butter: Adds richness and that classic creamy flavor we all expect in mashed potatoes.

Sour Cream: Gives the casserole a tangy depth and helps create that soft, melt-in-your-mouth consistency.
Milk or Heavy Cream: Thins out the mash to the perfect texture while keeping it luscious and silky.
Garlic Powder: Adds subtle flavor without overwhelming the dish. You can use roasted garlic for a deeper note.

Salt & Pepper: Simple seasoning that brings everything together.
Shredded Cheddar (optional): For a cheesy layer on top or mixed into the potatoes for extra indulgence.
Chives or Green Onions: A fresh garnish to brighten each bite.

How To Make the Mashed Potato Casserole

Step 1: Boil the Potatoes to Perfection

Peel and cube your russet potatoes, then boil them in salted water until they are fork-tender, about 15–20 minutes. Drain well.

Step 2: Mash and Blend

Transfer the hot potatoes to a mixing bowl. Mash them using a potato masher or ricer. Add in butter, sour cream, and milk or cream. Season with garlic powder, salt, and pepper. Blend until smooth and creamy.

Step 3: Assemble the Casserole

Preheat your oven to 350°F (175°C). Lightly grease your casserole dish. Spread the mashed potato mixture evenly into the dish. Sprinkle shredded cheddar on top if using.

Step 4: Bake Until Golden

Bake for 25–30 minutes until the top is slightly golden and the casserole is heated through. You can broil the top for the last 2–3 minutes if you want extra color.

Step 5: Garnish and Serve

Remove from the oven and let it sit for a few minutes before serving. Sprinkle with chopped chives or green onions for a burst of color and freshness.

How to Serve and Store Mashed Potato Casserole

Mashed Potato Casserole is the side dish that goes with everything—from roasted meats and grilled vegetables to festive holiday spreads. Serve it straight from the baking dish, hot and golden, with a drizzle of melted butter or a sprinkle of fresh herbs. It pairs especially well with gravy, turkey, ham, or even a hearty vegetable stew.

If you’re serving a crowd, this casserole holds its heat beautifully in a warm oven or covered with foil. For a fun twist, you can scoop it into individual ramekins for mini servings at dinner parties.

To store leftovers, let the casserole cool completely, then transfer it to an airtight container. It will keep in the refrigerator for up to 4 days. For freezing, wrap tightly in foil and plastic wrap and freeze for up to 1 month. Reheat in the oven at 350°F until warmed through, or microwave smaller portions.

Frequently Asked Questions

Can I make this ahead of time?

Absolutely! You can prepare the entire casserole a day in advance. Just cover and refrigerate it, then bake when you’re ready to serve. Add an extra 10 minutes to the baking time if it’s going straight from fridge to oven.

What’s the best type of potato to use?

Russet potatoes are best for a fluffy texture. Yukon Golds can also be used if you prefer a creamier, denser result.

Can I add other mix-ins?

Yes! Crumbled bacon, roasted garlic, or caramelized onions can be stirred in for extra flavor. You can even top it with crushed crackers or breadcrumbs for crunch.

Is it gluten-free?

Yes, as long as all your ingredients (like sour cream and cheese) are labeled gluten-free, this casserole is naturally gluten-free.

How do I reheat leftovers?

You can reheat in the microwave or oven. Add a splash of milk to maintain the creaminess and cover loosely with foil to prevent drying out in the oven.

Can I double the recipe?

Definitely. Just use a larger baking dish and extend the baking time slightly until it’s heated through.

Want More Casserole Ideas?

If this Mashed Potato Casserole hit the spot, check out these other cozy casseroles to keep the comfort food vibes going:

• Million Dollar Ravioli Casserole for a cheesy, meaty pasta bake that’s always a hit.
• Chicken Cordon Bleu Casserole for a creamy, savory twist on a French classic.
• Mexican Cornbread Casserole if you love Tex-Mex flavors packed into one dish.
• Scalloped Corn Casserole for something sweet, savory, and perfect for holidays.
• Cheesy Pizza Tater Tot Casserole for family-friendly, crispy-topped comfort.

Save This Recipe for Later

📌 Save this recipe to your Pinterest dinner board so you can come back to it anytime you need a reliable, cozy side dish.

And I’d love to hear how yours turned out. Did you add bacon or roasted garlic? Did you go extra cheesy?

Let’s chat in the comments—I always enjoy seeing your delicious spins on these recipes. And if you’re looking for more dinner inspiration, I share new favorites daily on Pinterest: Life With Olivia on Pinterest

Mashed Potato Casserole

Author: Olivia McKenney
Total Time: 50 minutes

Yield: 8 servings

Print Recipe

Description

This Mashed Potato Casserole is the ultimate side dish—creamy, buttery, and full of comforting flavor. Baked to golden perfection, it’s perfect for holidays or everyday meals. Make it ahead or freeze leftovers for later, and enjoy a classic with a rich, irresistible twist.