Loaded Cheesy Mashed Potato Casserole

Loaded Cheesy Mashed Potato Casserole is creamy homemade mashed potatoes stirred together with cheddar, Gruyère, sour cream and onion dip mix, then topped with more cheese and crispy bacon and baked until it’s melty.

Oh man, these were sooooo good. I’d been wanting to make a cheesy potato casserole for quite some time, and I’m happy to say that I nailed it! I make mashed potatoes all the time, and this is how I turn a pot of them into a side dish that earns its spot on the Thanksgiving table.

Just about every single time I plan out what I’m going to serve for dinner, it revolves around a protein, a starch, and a veggie. Do you do that too? This one covers the starch in a big way.

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What You’ll Need

• Golden potatoes. I use golden potatoes (Yukon Golds), which mash up creamy.
• Cheese. I use a cheddar and Gruyère blend, which I’ve only found at Trader Joe’s. Half grated cheddar and half grated Gruyère works just as well. Grate it from a block: pre-shredded cheese is coated to keep it from clumping in the bag, and it doesn’t melt as smoothly.
• Bacon. Cooked until crisp and crumbled, for the top.
• Butter, sour cream and milk for a creamy mash.
• Onion dip mix. I always have some in my pantry because it’s so good in recipes like this one. No dip mix? Use 1/2 teaspoon salt and 2 teaspoons granulated onion in place of the 2 tablespoons of mix.
• Garlic powder and freshly ground pepper.
• Green onions, sliced, for the top.

The onion dip mix brings plenty of salt for me, so the recipe doesn’t call for any extra. Full amounts are in the recipe card below.

The No-Peeler Potato Trick

I used to peel and chop my potatoes before I boiled them. Gone are those days! All I do now is score the skin all the way around, cover them in water, and boil until soft. Then, as soon as the potatoes are cool enough to handle, the skins slip right off. If you haven’t tried this method, I insist you must!

Cooking them whole also means they soak up less water than cut-up potatoes, so the mash stays creamy instead of watery.

PRO TIP: Score just through the skin, in one circle around the middle of each potato. The skin splits along that line, so it comes off in two pieces.

How to Make Loaded Cheesy Mashed Potato Casserole

It’s four steps: cook the potatoes, mash them, spread them in the dish, then top and bake.

Step 1: Cook and Peel the Potatoes

Boil the potatoes whole. Score a circle through the skin around the middle of each potato, cover them with water in a large pot, and boil until tender, about 20 to 30 minutes. Drain, let them cool enough to handle, and slip off the skins. While they cook, cook the bacon until crisp and crumble it.

Step 2: Mash With Half the Cheese

Mash everything together. In a large bowl, combine half of the cheese with the butter, sour cream, milk, onion dip mix, garlic powder and pepper. Add the warm potatoes and mash by hand until it’s as smooth as you like. A blender or food processor overworks the potatoes and makes them gluey. Taste, and add salt if you want it.

Step 3: Spread It in the Dish

Fill a buttered dish. Preheat the oven to 400°F, lovingly butter a 9×9 baking dish, and spread the potatoes in an even layer.

Step 4: Top and Bake

Add the toppings and bake. Sprinkle on the rest of the cheese and the bacon, and bake until the potatoes are heated through and the cheese has melted, about 5 to 10 minutes. Top with sliced green onions.

Oh yes. You see what I’m talking about now, don’t you? Trust me. These will be the best potatoes you’ve ever had.

How to Make It Ahead for Thanksgiving

I always prepare my Thanksgiving dinner the day before, so I can finish cooking with little mess on the day of. This casserole is made for that.

The day before: make it through the cheese and bacon topping, then cover the dish and refrigerate it.

On the day: bake it straight from the fridge at 400°F, covered with foil, for 20 to 30 minutes, until it’s hot in the center (165°F on an instant-read thermometer). Then take the foil off and bake 5 to 10 minutes more, until the cheese is melted. Add the green onions right before serving.

Keep it in the fridge until it goes into the oven. Mashed potatoes made with dairy and bacon shouldn’t sit at room temperature for more than 2 hours, so don’t assemble it in the morning and leave it on the counter until dinner.

★★★★★

This recipe has everything I love about traditional mashed potatoes, just taken to the next level!! This was absolutely delicious and a star at our holiday table!

Anjali, reader review

What to Serve With It

This is a Thanksgiving side through and through. Pile it next to oven roasted turkey (soaked overnight in my apple cider turkey brine), homemade green bean casserole and homemade cranberry sauce, with country mushroom gravy for spooning over the top.

It’s just as good on a weeknight with old fashioned meatloaf or smothered chicken and an easy vegetable. How much would you love this on your dinner plate? YUM!

Ways to Change It Up

• Swap in cauliflower. I haven’t made this exact recipe with cauliflower, but you can easily replace some or all of the potatoes with it. Cook the cauliflower until it’s tender enough to mash into a smooth texture.
• Try a different mash. For another side on the table, brown butter mashed potatoes and roasted garlic mashed potatoes are two more ways I make them.

Storing and Reheating Leftovers

Cover leftovers and refrigerate them within 2 hours of baking. They keep 3 to 4 days in the fridge. Reheat them in the oven or microwave until they’re hot all the way through (165°F).

What other potatoes can I use?

Russets work and make a fluffier, drier mash, so you may need a splash more milk. Red potatoes have thin skins too and make a denser, creamy mash.

How many slices of bacon is 8 ounces?

About 8 to 10 slices of regular-cut bacon, or 5 to 6 slices of thick-cut. It’s about half of a 1-pound package.

Can I make it in a 9×13 dish?

Yes. Double everything and use a buttered 9×13 dish. The layer will be a little deeper than in the 9×9, so if it’s going in cold from the fridge, it may need more time under the foil. Bake until the center reaches 165°F.

More Thanksgiving Recipes

Round out the table with these:

Homemade Green Bean Casserole

Sweet Potato Casserole

Homemade Cranberry Sauce

Oven Roasted Turkey