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closeup of scoop missing from casserole in a white dish

Mashed Potato Casserole

This cheesy Mashed Potato Casserole is a great recipe that is sure to be your new favorite side dish.
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Course: Vegetarian
Cuisine: American
Prep Time: 10 minutes
Cook Time: 15 minutes
Total Time: 25 minutes
Servings: 12 servings
Calories: 242kcal
Author: Jennifer Stewart

Equipment

Ingredients

  • 5 large Russet potatoes roughly 3 pounds
  • 1/2 cup sour cream
  • 1/2 cup milk
  • 1 large egg beaten
  • 6 tablespoons butter divided 4 tbsp + 2 tbsp
  • 1 cup panko crumbs
  • 4 ounces cheddar cheese shredded

Instructions

  • Preheat the oven to 375F. Prepare a 9x13 casserole dish with cooking spray.
  • Peel and dice the Russet potatoes. Place the potatoes in a large pot and cover with cold water.
  • Stir in 2 teaspoons salt if desired.
  • Bring the water to boil over high heat and cook until the potatoes are fork tender. Drain and return potatoes to the pot.
  • Gently mash the potatoes with a potato masher or large fork until most of the large pieces are gone.
  • Stir in the the milk, sour cream, beaten egg, cheese, and 4 tablespoons of butter. Mix to combine. Season with salt and pepper as desired.
  • Spread the potato mixture in the prepared baking dish.
  • In a small bowl, combine the panko with 2 tablespoons of melted butter. Sprinkle the buttered panko crumbs over the mashed potatoes.
  • Bake at 375F for 15-20 minutes or until the potatoes are hot and the top is golden brown.
  • Remove from the oven and enjoy!

Notes

  • Yukon Gold potatoes are great for this too with a rich yellow color and buttery flavor.
  • If using leftover mashed potatoes, combine everything in a large bowl for mixing.
  • Want to spice up the flavors of this casserole a little more? You can add in garlic powder or garlic salt for more of a kick!
  • Love onions? Add in some onion powder to more flavor.
  • Sharp cheddar cheese adds a great contrast to the creamy potatoes.
  • If you want the creamiest mashed potatoes, add in some cream cheese to make the consistency even thicker and more rich. 
  • For my cheese lovers out there, you can add a cup of cheddar cheese on top with your panko crumbs, giving this casserole a gooey and melty topping that will be a hit for any big cheese lovers.
  • Don’t forget to salt your cold water when cooking your potatoes to give them some extra flavor!
  • You can make this baked potato casserole in the slow cooker too!
    • The original recipe first appeared on Leftovers Then Breakfast.

    Nutrition

    Serving: 1g | Calories: 242kcal | Carbohydrates: 34g | Protein: 8g | Fat: 8g | Saturated Fat: 4g | Polyunsaturated Fat: 3g | Cholesterol: 36mg | Sodium: 174mg | Fiber: 3g | Sugar: 3g