Twice Baked Potato Casserole

Once the cheese starts bubbling around the edges, the whole casserole smells like a baked potato with its best toppings already in place. The trick is getting the potatoes fluffy before they meet the sour cream and milk; a watery mash makes the finished dish heavy instead of creamy. I bake the russets whole, then scoop out the centers and mash them with butter, sour cream, and milk for this Twice Baked Potato Casserole.

Sharp cheddar goes both into the potato mixture and over the top, so you get cheese in every bite and a melted layer across the surface. Crisp bacon adds a salty crunch, while green onions bring a fresh finish. It’s a generous casserole for eight, and it comes together with familiar ingredients and a few clear texture cues: tender potatoes, creamy mash with a few small lumps, and bubbling edges.

Why Baking the Russets First Keeps This Casserole From Turning Watery

Russet potatoes are starchy and bake up fluffy, which is exactly what you want before folding in sour cream, milk, and butter. Baking them whole means the potato flesh cooks without being submerged in water. That matters here: potatoes that carry extra moisture can make the mash loose, and a loose mash stays soft instead of setting into a scoopable casserole.

The potatoes also need to be fully tender before you mash them. A knife should slide easily into the center; if you pull them while the middle is still firm, those pieces are difficult to mash evenly and can leave hard bits in the finished dish. Once they’re tender, keep the mash a little rustic. Creamy potatoes with a few small lumps hold their body better than a mixture worked until completely smooth.

There’s a second bit of balance in the layering. Some cheddar goes into the potatoes, where it melts through the mash, and the rest covers the top with the bacon. You get a creamy interior and a cheesy finish without relying on extra liquid to loosen the potatoes.

What Russets, Sour Cream, and Sharp Cheddar Each Bring

• Russet potatoes — Their fluffy texture makes a light mash that can hold the dairy and cheese. Choose firm potatoes without soft spots; there isn’t a clean swap from the ingredients here that gives quite the same result. Scrub them before baking, then scoop out the flesh once they’re cool enough to handle.
• Sour cream and whole milk — Sour cream brings tang and a thick, rich feel, while whole milk loosens the mash without taking away its body. Use thick sour cream; the brand matters less than its consistency. The listed ingredients don’t offer a direct substitute for sour cream, so I wouldn’t try to replace it with extra milk—the result would lose that tang and could turn loose.
• Sharp cheddar — Its stronger flavor comes through the creamy potato instead of disappearing into it. Shredded cheddar is convenient, and freshly shredded cheese tends to melt more evenly than packaged shreds. Keep the cheese divided between the mash and the topping so the inside and surface both get their share.
• Bacon and green onions — Cook the bacon until crisp so it brings a distinct crunch to the soft potatoes; drain it before crumbling. Fresh green onions add a mild, sharp finish after baking. If you’re leaving out bacon for a meat-free version, the green onions still give the top a fresh contrast.

From Baked Potatoes to a Bubbling Casserole

Roast the Potatoes and Crisp the Bacon

Heat the oven to 400°F. Prick the scrubbed russets several times with a fork, set them on a rimmed baking sheet, and bake for 55–70 minutes, until a knife slides easily into the centers. While they bake, cook the bacon in a 10-inch skillet over medium heat for 8–10 minutes, turning it occasionally until crisp. Drain the bacon, then crumble it once it’s cool enough to handle.

Scoop and Mash the Potato Flesh

Let the potatoes cool for about 10–15 minutes, until they’re easy to handle. Grease a 9×13-inch baking dish with 1 tablespoon of softened butter, halve the potatoes lengthwise, and scoop the flesh into a large bowl; discard the skins. Add the remaining butter with the sour cream, milk, salt, and pepper, then mash until creamy with a few small lumps. Fold in 1 1/2 cups of the cheddar, taking care not to mash the cheese into a paste.

Layer the Cheese and Bacon

Spread the potato mixture evenly in the buttered baking dish so it heats at a steady pace. Scatter the remaining cheddar over the surface, then add the crumbled bacon. Distribute both toppings across the dish rather than leaving a thick pile in the middle.

Bake Until the Edges Bubble

Return the dish to the 400°F oven and bake for 25–30 minutes. Look for melted cheese, bubbling edges, and a hot center; if the edges are bubbling but the center isn’t hot yet, give it more time in the oven. Sprinkle the green onions over the top and let the casserole rest for 10 minutes before serving.

Two Simple Ways to Change the Potato Casserole

Questions That Come Up When Making Twice Baked Potato Casserole

Twice Baked Potato Casserole

Twice baked potato casserole combines creamy, lightly lumpy russet potatoes with sharp cheddar and crisp bacon. Baked in a 9x13-inch dish until bubbling, it’s finished with thinly sliced green onions.

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Prep Time 20 minutes mins

Cook Time 1 hour hr 30 minutes mins

Cooling and resting 25 minutes mins

Total Time 2 hours hrs 15 minutes mins

Servings: 8 servings

Course: Side Dish

Cuisine: American

Calories: 430

Ingredients Equipment Method Notes

Ingredients

  

For the casserole

• 3 lb russet potatoes scrubbed
• 5 tbsp unsalted butter softened and divided (1 tablespoon for the baking dish and 4 tablespoons for the potatoes)
• 1 cup sour cream
• 0.5 cup whole milk
• 1 tsp kosher salt
• 0.5 tsp black pepper

For the topping

• 2.5 cups sharp cheddar cheese shredded and divided (1 1/2 cups for the potato mixture and 1 cup for the topping)
• 6 slices bacon
• 4 green onions thinly sliced

Equipment

• 1 rimmed baking sheet
• 1 10-inch skillet
• 1 9x13-inch baking dish

Method

 

Bake the potatoes

1. Preheat the oven to 400°F.
2. Prick the potatoes several times with a fork and place them on a rimmed baking sheet.
3. Bake the potatoes for 55–70 minutes, until a knife slides easily into the centers.
4. Cook the bacon in a 10-inch skillet over medium heat for 8–10 minutes, turning occasionally, until crisp.
5. Drain and crumble the bacon.

Assemble and bake

1. Let the potatoes cool until easy to handle, about 10–15 minutes.
2. Grease a 9x13-inch baking dish with 1 tablespoon of the butter.
3. Halve the potatoes lengthwise and scoop the flesh into a large bowl, discarding the skins.
4. Add the remaining 4 tablespoons butter, sour cream, milk, salt, and pepper, then mash until creamy with a few small lumps.
5. Fold 1 1/2 cups of the cheddar into the potato mixture.
6. Spread the potato mixture evenly in the prepared baking dish.
7. Sprinkle the remaining 1 cup cheddar and the crumbled bacon over the potatoes.
8. Bake at 400°F for 25–30 minutes, until the cheese is melted, the edges are bubbling, and the center is hot.
9. Sprinkle with the green onions.
10. Let the casserole rest for 10 minutes before serving.

Notes

For the creamiest texture, mash the potatoes only until creamy with a few small lumps. Refrigerate leftovers for 3–4 days; freeze for up to 2 months. For a lactose-free option, use lactose-free sour cream and milk.