Leftover Baked Potato Casserole
Use up leftover baked potatoes in a casserole that feels fresh and new. Packed with all the “loaded” flavors of bacon, green onions, cheddar cheese and sour cream this is a fun way to make leftovers shine.
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- Russet potatoes are best
- Don’t over mash the potatoes or they will release too much starch and get gluey
- Feel free to leave the skins on if you want extra fiber.
- For added flavor, add homemade ranch seasoning, fresh herbs or strong/spicey cheeses like blue or pepper jack and panko bread crumbs add crunch.
- Add cooked meat like chopped chicken, pulled pork or cooked ground beef if you’d like.
- For a thicker casserole use a 7×11 or a 9×13 for a thinner one.
- To make ahead: Assemble the casserole, cover the baking dish with saran wrap, and store it in the refrigerator for up to 3 days.When you are ready to serve, pop it in the cold oven as it preheats to 350 degrees F and bake until the cheese is melty.
- To freeze: Allow the casserole to cool to room temperature before wrapping the baking dish in a double layer of plastic wrap followed by a layer of aluminum foil. Store it in the freezer for up to 3 months. To reheat, allow the dish to thaw in the refrigerator overnight. Unwrap the thawed casserole and pop it in the oven at 350 degrees F until heated through.

What to serve with leftover baked potato casserole
This hearty dish plays beautifully with enumerable entrees and side dishes. Here are some of my favorite things to serve it with.
- Apple cider pork chops
- Vinegar-brined grilled chicken
- Air fryer salmon
- Orange ginger roasted asparagus
- Brown butter Brussels sprouts

Leftover Baked Potato Casserole
Ingredients
- 8 medium russet potatoes about 8 ounces each
- 1/2 cup butter 1 stick, softened
- 2/3 cup cultured sour cream
- 2/3 cup milk
- 1 teaspoon sea salt Celtic sea salt is best
- 3/4 teaspoon pepper
- 10 bacon strips uncured is best, cooked and crumbled
- 2 cups shredded aged cheddar cheese do not use pre-shredded cheese
- ¼ cup chopped green onions
Instructions
If you need to bake potatoes first:
- Preheat the oven to 425 degrees.
- Scrub potatoes and poke several times with a fork.
- Bake until tender, 45-60 minutes. You can also air fry them if you’d like to.
- Remove the potatoes from the oven and reduce the heat to 350.
- When potatoes are cool enough to handle each one in half down the length.
If you have leftover potatoes:
- Using a spoon, scoop out the pulp and add it to a large bowl. You can throw away the skins or chop them small and throw them in too.
- Using a fork or hand masher, mash the potatoes with the butter. Stir in the sour cream, milk, salt, and pepper.
- Save ¼ cup of the bacon mixture for topping but add the rest to the potatoes. Add in 1 cup of cheese and half the green onions and fold gently to combine. Don’t over mix or the potatoes may get gluey.
- Transfer the potatoes to a lightly greased 11×7 baking dish. Add the remaining bacon, cheese and green onions on top and bake until the cheese melts and everything is heated through 22-27 minutes.
Disappointed – I thought that this recipe was for baked potatoes that you had leftover from another meal, but baked potatoes are part of the ingredients and steps. Since you have to bake potatoes first for an hour, and then the casserole for 30 minutes, I don’t see how the time for this recipe is 1.5 hours – closer to 2-2.5 when all is done.
There’s no need to bake the potatoes fresh. It’s meant for exactly what you said and leftover potatoes can be used with no changes to the recipes. We included steps for baking for people who might need them. All cold leftover spuds are welcome here!
Does this casserole freeze well? I’m assuming you would allow it to defrost and then bake at 350 for the 22-27 minutes?
Shela I’ve never frozen it so I can’t say for sure but I think it would probably be fine. –Rachel
This was SO easy, and surprisingly tasty! My husband, who says that most casseroles give him hives (haha), loved it– he kept sneaking bites out of the dish after dinner while we were cleaning up! It seems quite flexible, I just eyeballed the ratio of butter/milk/sour cream to the leftover potatoes I had until the texture looked like the photos and it came out perfect. I was even able to combine 2 different leftover potato dishes (regular baked jacket potatoes and smashed sheet-tray roasted small potatoes) with very different textures, and it came together beautifully. I am glad I chopped up the skins to include, it improved the texture. This recipe is a keeper and will be a great quick addition to a busy weeknight meal.
Great recipe!! Family loved it! I always have leftover baked potatoes this is my go to recipe from now on. Thank you
Could you use this as part of a shepherds pie? I have a lot of leftover baked potatoes/home friends and left over beef – wondering if I could do a layer of beef below the potatoes and maybe some veggies on top!
Yes Nicola I think that would be really good!
Just wondering why you can’t use already shredded cheese–I’m sure there’s an obvious reason that I’m just not seeing! This sounds yummy and I have potatoes left from a potato bar I provided today, so I want something different!
Hey Susan, pre shredded bagged cheese is coated in an anti caking agent called cellulose that when melted can cause the cheese to become gluey or not melt at all. I just gave up on bagged cheeses a long time ago because the melting issues were getting worse and worse and just grate it from a block. –Rachel
Just wondering… at what temperature do you bake the final 22-27 minutes? At 350 or 425??
It’s 350 for that Carol. 425 was only for baking the potatoes, then you reduce the heat and assemble the recipe and finish baking at the lower temperature. –Rachel