This Mashed Potato Casserole elevates an ordinary batch of creamy mashed potatoes into something absolutely divine topped with cheddar, bacon bits, and green onions. It has all of the flavors of a fully loaded baked potato, but in casserole form. It's such a fun dish and the perfect way to elevate your side dish game for your next holiday meal!
Mashed Potatoes are a must-have for any big family dinner. They're the ultimate comfort food: so warm and inviting with lots of creamy toppings and flavors. This Mashed Potato Casserole recipe is perfect for your Thanksgiving dinner because it's perfectly seasoned and ready to serve exactly as it is. No need for gravy for anything else!
Why You'll Love This Mashed Potato Casserole
- So easy. If you can boil potatoes, you can make this potato side dish. It starts by making regular mashed potatoes, but then you add leftover bacon fat, milk, butter, and sour cream. Mash well then bake with shredded cheese and crispy bacon bits on top. Add a garnish of green onions for color. It's so flavorful and creamy!
- Tons of flavor. This recipe uses some of the most flavorful ingredients, like real butter, milk, bacon, sour cream, and more. There is one secret ingredient, though! After cooking the bacon, we actually add the leftover bacon grease into the potatoes to add that savory bacon flavor into every bite. So good!
- Family favorite. Be prepared to get lots of compliments on this easy casserole, and save this recipe because you'll be asked to make it again and again!
Ingredient Notes
To make this delicious Mashed Potato casserole recipe, you will need the following ingredients (full measurements in recipe card below):
- potatoes - use yukon gold or russet potatoes from the creamiest texture. Peel and cut your potatoes into 1-inch pieces.
- bacon - slice your bacon in half to help it cook more quickly.
- whole milk - the milk will soften the mashed potato mixture and give it a creamy texture. You can substitute with heavy cream for an even creamier texture.
- butter - use unsalted butter and cut into 1-inch pieces to help it melt evenly.
- sour cream - this adds a rich creaminess and a little tanginess.
- salt and pepper - season well. Potatoes need a lot of salt to have any flavor.
- cheddar cheese - shred sharp cheddar cheese for a molten cheese layer on top of the warm potatoes.
- green onions - finely chop green onions or fresh chives for a little color and a fresh flavor.
You will also need large pot, strainer, potato masher, large skillet, bowl, paper towels, plate, cutting board and knife, and a 2-quart casserole dish..
How to Make the Best Mashed Potato Casserole
- Cook potatoes. Place potatoes in a large cooking pot and cover with salted water, covering the potatoes by about an inch. Bring to a boil over high heat. Reduce heat to low, cover, and simmer for 15-20 minutes, until potatoes are soft when you insert a fork. Drain well and place back into the pot.
- Cook the bacon. While the potatoes are cooking, add bacon in a skillet and cook over medium-high heat until browned on both sides and crisp, about 6-8 minutes. Reserve the bacon fat in a bowl and transfer the bacon onto a paper towel lined plate. Chop the bacon into 1-inch bits.
- Combine the ingredients. Once the potatoes are ready, drain well and place back in the pot. Use a potato masher (or a fork) to mash the potatoes. Add milk, butter, sour cream, salt, pepper, and reserved bacon fat. Stir well with a spatula until evenly combined.
- Add toppings. Transfer the mashed potato into a 2-quart casserole dish and top with cheddar cheese and bacon bits.
- Bake. Cover with foil and bake in a 375 F preheated oven for 20 minutes. Remove the foil and bake uncovered for another 10 minutes until the melted cheese is bubbly.
- Serve. Garnish with green onion and serve warm.
Recipe Variations
- Use cream cheese. Instead of sour cream, add cream cheese or even mayonnaise!
- Make a crunchy topping. Combine crunchy panko breadcrumbs and melted butter like the topping for this Chicken Divan recipe.
- Make it garlicky. Add roasted garlic cloves, garlic powder, or garlic salt to the mashed potatoes for an extra flavor.
- Use leftover mashed potatoes. This is a great way to repurpose any leftover mashed potatoes. Just spread your mashed potatoes in a casserole dish, add the tpppings, and bake.
How to Serve
This mashed potato casserole is delicious served on its own, or served as part of a holiday meal paired with more side dishes including:
- Green Bean Casserole
- Classic Homemade Turkey Gravy
- Corn Casserole
- Cranberry Walnut Apple Stuffing
- Cornmeal Cheddar Biscuits
For more recipe inspiration, see our 50 Best Thanksgiving Side Dishes.
Recipe Tips and Tricks
- Don't overmix the mashed potatoes. If you blend the potatoes or mash them too much, they take on a really unpleasant gluey texture.
- Use a stand mixer. One great way to get really fluffy mashed potatoes is to whip them in the bowl of a stand mixer or with an electric mixer. This gives them a really light and airy texture.
- Start with cold water. An old trick to get the creamiest mash potatoes is to start the potatoes in cold water. This will allow the potatoes to soften gradually, becoming really soft and fluffy.
Storing and Freezing Instructions
How to Store
Place any leftover potatoes in an airtight container in the fridge for 3-4 days.
How to Reheat
Either microwave a serving for 2-3 minutes or pop them in a preheated 375F oven with a fresh sprinkle of cheese for 8-10 minutes until warm and the cheese is melted.
How to Freeze
Freeze chilled leftovers in a freezer safe container for 2-3 months. Thaw in the fridge overnight before reheating the next day.
FAQ
The best potatoes for mashed potatoes are really starchy varieties like Russets or Yukon Gold potatoes. Red potatoes are some of the least starchy potatoes, so they have a harder time becoming really light and fluffy. With that said, you can use them for mashed potato casserole, but just be aware they will not have the same level of creaminess.
Absolutely! Have you ever noticed how some dishes taste better the next day? As these cheesy potatoes sit in the fridge overnight, all of the flavors meld together. They taste amazing the next day!
With so many flavor-packed ingredients and baked potato toppings, your baked potatoes casserole should be really flavorful. If it isn't, there are likely a couple of reasons why. First, potatoes need a lot of salt. Boil the potatoes in salted water, then taste and season them several times as you're cooking. If you season as you go, your cooked potatoes will have plenty of flavor. Another thing to consider is the fat content of the dairy products you use. If you choose low fat or fat free options, you'll struggle to get the same luxurious creaminess as when you use full fat dairy products.
More Potato Recipes
- 30 Potato Side Dishes
- Brown Butter Mashed Potatoes
- Potato Stacks
- Baked Potato Wedges
- Hasselback Potatoes
- Duchess Potatoes
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