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.
Russet potatoes on a counter.

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

Adding sour cream and butter to a pot of mashed potatoes.
Mashed potatoes mixed with sour cream and butter.
Mashed potatoes spread in a casserole dish.
Mashed potatoes topped with cheese and bacon.

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.

A baking dish covered with cheese, bacon, and green onions.

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.
Close up of a casserole dish of loaded mashed potato casserole topped with cheese, bacon, and green onions.
A mashed potato casserole topped with cheese and green onion.
5 from 123 votes

Mashed Potato Casserole Recipe

By: Kristyn Merkley
Mashed Potato Casserole is a creamy, cheesy 9×13 side dish with sour cream, cream cheese, cheddar, parmesan, bacon, and green onions.
Servings: 12
Prep: 35 minutes
Cook: 20 minutes
Total: 55 minutes

Equipment

Video

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!
Save This Recipe!
Just enter your email and get it sent to your inbox! Plus you’ll get new recipes from us every week!

Notes

    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.
    Make ahead of time. We recommend making this no more than 48 hours in advance, cover and refrigerate. Cook until warmed throughout. 
    Store. Store leftovers in an airtight container in the fridge for 3-5 days. 
    Freeze. 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.

    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

    Make ahead of time?

    We recommend making this no more than 48 hours in advance, cover and refrigerate. Cook until warmed throughout.

    How to store?

    Store leftovers in an airtight container in the fridge for 3-5 days.

    How to freeze?

    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

    Collections

    This recipe was first shared October, 2015.

    Categorized as: , , , , , , , , ,

    About Kristyn

    Kristyn Merkley is a published cookbook author, wife, mom of six, and major food enthusiast! For the past 15 years, she has been sharing foolproof, family-friendly recipes—each one tested in her kitchen—that anyone can master. As a seasoned recipe creator, she loves making cooking simple, stress-free, and totally doable for everyone!

    More About Kristyn

    Get my cookbook!

    My cookbook is the ultimate resource for feeding your friends and family with 200+ simple recipes with videos, tips & more!

    Order Today
    5 from 123 votes (58 ratings without comment)

    Leave a comment

    Your email address will not be published. Required fields are marked *

    Recipe Rating




    104 Comments

    1. Christina says:

      I love cheese and I love mashed potatoes, so I gave this a 5 star rating, good cooking!

      Reply
    2. Erin says:

      5 stars
      So so good! The fam gobbled it up, and I finished the rest, so there were no leftovers 🙂

      Reply
    3. Mel says:

      5 stars
      The most perfect side ever! This had so much flavor and was so easy to make. Cannot wait to make this again!

      Reply
    4. Ellie Grove says:

      5 stars
      This is the perfect way to make a large amount of soft and fluffy potatoes for a crowd! It made the best side dish.

      Reply
    5. Linda says:

      Thanks for a delicious make ahead dish

      Reply
    6. Wendy Brunell says:

      5 stars
      This recipe is a perfect make-ahead for Easter dinner. It’s mashed potatoes so already a comfort food and then the addition of cheese and bacon?? So good.

      Reply
    7. Donna Fitschen says:

      5 stars
      This casserole is amazing! Love that you can make ahead of time! Sooo creamy and taste delicious! What a hit!

      Reply
    8. Ruth Buck says:

      5 stars
      We love this casserole

      Reply
    9. Lynne Willett says:

      5 stars
      Made it fir Christmas dinner and was so tasty and held/ transported so well

      Reply
    10. Gail says:

      This sounds delicious – I love Stuffed Potatoes and going to try this when I have a crowd. Thanks for sharing

      Reply
      1. Lil'Luna Team says:

        You’re welcome! Hope you enjoy!

        Reply