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Deliciously cheesy mashed potato casserole is a comforting twist that takes a classic side dish to a whole new level!

Close up of a casserole dish of loaded mashed potato casserole topped with cheese, bacon, and green onions.
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WE LOOOVE THEM!

We love Mashed Potatoes (in fact, we are strong believers they are the real star of Thanksgiving), but put them in casserole form and add even more cheese and goodness, and we promise you’ll be obsessed with today’s Mashed Potato Casserole.

This potato side dish is a casserole version of Mashed Potatoes and Twice Baked Potatoes combined and is the perfection addition to your holiday meal. Plus, it’s simple and can be made ahead of time making it holiday perfection.

WHY WE LOVE IT:

  • DELICIOUS!! With butter, potatoes, bacon, cheese, cream cheese, sour cream, and more – what’s not to love? The flavor is incredible!
  • Make ahead of time. We love this for holidays and love that it can be made in advance, which is great for busy weeks and get-togethers.
  • Feeds a crowd. It’s great for company since it feeds a lot, making is perfect for holidays like Thanksgiving and Christmas.
Russet potatoes on a counter.

Ingredients

  • 5 pounds potatoes – Russet potatoes and Yukon Gold potatoes are preferred – they have a perfect amount of starch which helps create creamy, flavorful potatoes.
  • 1 cup sour cream – use full-fat sour cream.
  • ½ cup butter – salted or unsalted work great, but you may need more salt if you’re using unsalted butter.
  • 8 ounces cream cheese
  • ½ cup milk – use 2% or higher for this recipe.
  • 2 teaspoons garlic salt (with parsley flakes)
  • black pepper – to taste
  • 12 slices cooked bacon – We prefer to make Bacon in the Oven but you can also use a microwave bacon if you’re in a rush.
  • 2 cups cheddar cheese – use other cheeses or a blend of your favorites including Mozzarella and Italian blend.
  • ½ cup parmesan cheese
  • garnish – green onion, chives, or other fresh herbs work great.

How to Make Mashed Potato Casserole

  1. POTATOES. Peel and cube 5 pounds 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.
  2. 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.
  3. 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.
  4. 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.
  5. TOPPINGS. Garnish with green onions or chives.
A baking dish covered with cheese, bacon, and green onions.

Complete the Meal

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5 from 120 votes

Mashed Potato Casserole

By: Lil’ Luna
Deliciously cheesy mashed potato casserole is a comforting twist that takes a classic side dish to a whole new level!
Servings: 12
Prep: 35 minutes
Cook: 20 minutes
Total: 55 minutes

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!

Video

Notes

Make ahead of time. We recommend making this no more than 48 hours in advance, covering and refrigerating. Cook until warmed through out.
STORE leftovers in an airtight container in the fridge for 3-5 days.

Nutrition

Calories: 469kcal, Carbohydrates: 25g, Protein: 15g, Fat: 34g, Saturated Fat: 18g, Cholesterol: 89mg, Sodium: 883mg, Potassium: 912mg, Fiber: 4g, Sugar: 1g, Vitamin A: 855IU, Vitamin C: 21.7mg, Calcium: 296mg, Iron: 6.5mg

Nutrition information is automatically calculated, so should only be used as an approximation.

Recipe FAQ

  • It may depend on how much your family loves mashed potatoes. Here is a quick guide to help:
    • 10 people – 1 dish
    • 20-25 people – double recipe
    • 35-40 people – triple recipe
  • 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.
    • To reheat. 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.

Recipe adapted from McCormick

About Kristyn

My name is Kristyn and I’m the mom of SIX stinkin’ cute kids and the wife to my smokin’ hot hubby, Lo. My mom’s maiden name is Luna, and I’m one of the many crafty “Lil’ Lunas” in the fam. On this site I like to share all things creative - from recipes to home decor to gifts and home decor ideas. Welcome!

So Easy & So Yummy

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5 from 120 votes (58 ratings without comment)

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Recipe Rating




95 Comments

  1. Maureen says:

    5 stars
    This is a must make for our anniversary tomorrow. My husband loves mashed potatoes and adding cheese just takes them up a notch. This will be enjoyed by my daughter, brother and sister in law, and of course the happy 56 years anniversary couple. Sure to be a hit.

  2. Amy says:

    5 stars
    Yum! I’m putting these on the menu!

  3. KEEN says:

    5 stars
    Can I make it up a day before and not cook until the next day?

  4. Maureen says:

    5 stars
    I think my grandson would really love these and considering making them for Thanksgiving. Cheese goes with everything.

  5. Carly says:

    5 stars
    These are the best! I have been making them for years for our Friendsgiving. 🙂

  6. Michelle Marie Bagby says:

    5 stars
    Girl thanks for these, with Easter coming up and needing to expand the table, these will come in handy and I KNOW that whatever I make from you will always be terrific! No guesswork or worry!
    I used many of your Fiesta recipes for our Anniversary celebration at church with 60 guests. It was again, what was that word…oh yeah, TERRIFIC!
    Thank you!

    1. Lil'Luna Team says:

      Awe, thanks for saying that!! That means a lot!!

  7. Marian says:

    5 stars
    Very good!

    1. Lil'Luna Team says:

      Glad you think so! Thank you!

  8. Siddiqa says:

    5 stars
    Sounds delicious! Will definitely try it without bacon. Thanks for the great recipes!

    1. Lil'Luna Team says:

      You are so welcome!! And, you can definitely leave the bacon off & it will still taste great! Enjoy!

  9. Jeanna Grover says:

    5 stars
    Great recipe, especially when I have leftover baked potatoes. Very simple to use them instead of cooking a fresh batch of potatoes. My family loves this recipe. Thank you for a delicious and quick recipe!!!

    1. Lil'Luna Team says:

      You are so welcome!! I’m glad your family likes them!!

  10. Debby says:

    5 stars
    These are great. My family will love and I’m adding to my Easter menu! Thanks for another great casserole idea.

    1. Lil'Luna Team says:

      You are so welcome!! I hope it’s a hit!!

      1. Liz says:

        5 stars
        Hi,

        I’ve made this recipe for years and I love it!

        I do have a question though – does it matter if we boil the potatoes like the instructions above or steam them in the instapot?