Today’s Mashed Potato Casserole is the ultimate creamy, cheesy potato side dish! It’s a Merkley favorite and one we make for so many holidays.
It’s loaded with sour cream, cream cheese, cheddar, parmesan and bacon. Yes, all the best things in one delicious dish! It has all the flavors of loaded mashed potatoes baked into an easy 9×13 casserole, which means we love making it for Thanksgiving, Christmas, Easter, Sunday dinners, and potlucks.
With so many great ingredients, it’s not only delicious but feeds a crowd and can be prepped ahead, making it one of our favorites to prep for the holidays.
For more favorite potato sides, be sure to check out our Funeral Potatoes, Twice Baked Potato Casserole, and classic Mashed Potatoes.
Why You’ll Love It + Why it works:
- Feeds a Crowd: Bakes in a 9×13 pan, making it perfect for holidays and potlucks.
- Make Ahead and Save Time: Great make-ahead side dish for busy family dinners and holiday meals.
- Cream Cheese and Sour Cream Keep it Creamy: They add richness and help the potatoes stay soft after baking.
- Cheese and Bacon go Inside and on Top: Mixing some in and saving some for the topping gives flavor in every bite and a pretty finish.
Mashed Potato Casserole Ingredients
- Potatoes, peeled and cubed (5 pounds): Creates the creamy mashed potato base and make the casserole hearty.
- Sour cream (1 cup): Adds creaminess and tang to the mashed potatoes.
- Butter (½ cup): Adds buttery flavor and helps make the potatoes smooth.
- Cream cheese, cubed (8 ounces): Makes the casserole extra creamy and rich. We always use full fat cream cheese.
- Milk (½ cup): Helps loosen the potatoes and create a smooth texture.
- Garlic salt with parsley flakes (2 teaspoons): Seasons the potatoes with garlic flavor, salt, and a little herb flavor.
- Pepper (to taste): Adds seasoning and balances the richness.
- Bacon, cooked, chopped, and divided (12 slices): Adds smoky flavor and a delicious topping. We prefer to make Bacon in the Oven but you can also use a microwave bacon if you’re in a rush.
- Cheddar cheese, divided (2 cups): Melts into the potatoes and creates a cheesy topping.
- Parmesan cheese (½ cup): Adds salty, nutty flavor and makes the potatoes even more flavorful.
- Green onions, for garnish: Add freshness, color, and a loaded baked potato finish.
How to Make Mashed Potato Casserole
POTATOES. Peel and cube 5 pounds of potatoes. Place in a large pot and add water until just covering potatoes. Bring to boil. Once boiling, reduce to a simmer and cook for 18-20 minutes.
MASH. Drain water and mash potatoes using a potato masher or spoon (do not over-mix or potatoes will become gummy). Add 1 cup sour cream, ½ cup butter, 8 ounces cream cheese, and ½ cup milk until well combined.
SEASON. Add 1 teaspoon garlic salt, and black pepper to taste. Fold in ½ of the cooked bacon, 1 cup cheddar cheese, and ½ cup parmesan cheese. Stir well.
BAKE. Spoon into a lightly greased 9×13 pan. Top with remaining shredded cheddar cheese and the rest of the bacon. Bake at 350°F for 20-25 minutes.
TOPPINGS. Garnish with green onions or chives.
Kristyn’s Recipe Tips
- Cut the potatoes into similar-size cubes so they cook evenly.
- Drain the potatoes well before mashing so the casserole does not turn watery.
- Add the sour cream, butter, cream cheese, and milk while the potatoes are warm so everything melts together smoothly.
- Save half the bacon and some cheddar for the top so the casserole looks extra delicious.
- Make-ahead tip: assemble the casserole earlier in the day or the day before, cover and refrigerate, then bake when ready, adding extra time if it starts cold.
Mashed Potato Casserole Recipe
Equipment
Ingredients
- 5 pounds potatoes, peeled and cubed
- 1 cup sour cream
- ½ cup butter
- 8 ounces cream cheese, cubed
- ½ cup milk
- 2 teaspoons garlic salt (with parsley flakes)
- pepper to taste
- 12 slices bacon, cooked, chopped, and divided
- 2 cups cheddar cheese, divided
- ½ cup parmesan cheese
- green onions, for garnish
Instructions
- Peel and cube potatoes.
- Place in pot and add water until just covering potatoes. Bring to boil. Once boiling, reduce to a simmer and cook for 18-20 minutes.
- Drain water and mash potatoes using a masher or spoon. Add sour cream, butter, cream cheese, and milk until well combined. Add salt and pepper. Fold in ½ the bacon, 1 cup cheddar cheese, and parmesan cheese. Stir well.
- Spoon into a lightly greased 9×13 pan. Top with remaining cheddar cheese and the rest of the bacon.
- Bake at 350°F for 20-25 minutes. Garnish with green onions and ENJOY!
Notes
- Cut the potatoes into similar-size cubes so they cook evenly.
- Drain the potatoes well before mashing so the casserole does not turn watery.
- Add the sour cream, butter, cream cheese, and milk while the potatoes are warm so everything melts together smoothly.
- Save half the bacon and some cheddar for the top so the casserole looks extra delicious.
- Make-ahead tip: assemble the casserole earlier in the day or the day before, cover and refrigerate, then bake when ready, adding extra time if it starts cold.
Nutrition
Recipe FAQ
We recommend making this no more than 48 hours in advance, cover and refrigerate. Cook until warmed throughout.
Store leftovers in an airtight container in the fridge for 3-5 days.
To freeze, simply spread them into a freezer Ziploc bag and squeeze out as much air as possible. They’re best when used within 6-8 weeks, but can last for up to 4 months.
Let potatoes thaw in the fridge overnight. Place potatoes in a casserole dish and bake at 350°F for about 25 minutes. Add additional cheese and top and bake for an additional 5 minutes.
More Like This
Serve With
Potato Dishes
Make Ahead Mashed Potatoes
1 hr 45 mins
Crockpot Cheesy Potatoes
4 hrs 5 mins
Best Mashed Potatoes
35 mins
Funeral Potatoes
1 hr 5 mins
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This recipe was first shared October, 2015.
Just made this for my family. Amazing!!! A new favorite. Thank you for sharing. You
Woohoo! These are our favorite! Glad your family liked them! Thank you!
I know what I will be having for dinner tonight! This looks hands down delicious!
Heart be still, this looks incredible, must make asap!
My favorite way to make mashed potatoes! Always a hit!
This casserole was a huge hit with my whole family – our new obsession!
These potatoes are so creamy! I love it!
Potatoes are well loved around here! Adding to the menu plan!
Same around here!! Enjoy!
Hands down my favorite side dish!
One of mine too!! Thank you!
I love just about any type of potatoes, but these look especially good. You can’t go wrong with bacon and cheese in my book!
No, you can’t go wrong with that! 🙂 Thank you!!
Theres nothing I like better than to make something stick it in the fridge and then bring it out to bake. Especially mashed potatoes. Its always one of those dishes that Im trying to keep warm. Love this recipe!