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Creamy Mashed Potato Casserole

Creamy Mashed Potato Casserole gets a little flavor love with the addition of sour cream and cream cheese.
5 from 2 votes
Prep Time 10 minutes
Cook Time 20 minutes
Reheating Time 45 minutes
Course Side Dish
Servings 12


  • 5 pounds russet potatoes, about 6 bakers peeled and cut into 6-8 pieces each
  • 4 sprigs fresh thyme
  • 4 garlic cloves peeled
  • 1 bay leaf
  • 1 Tablespoon kosher salt
  • 1 stick butter (1/2) cup, plus 2 Tbl. for top of casserole room temperature
  • 8 ounces cream cheese room temperature
  • 1 cup sour cream
  • 1 cup whole milk
  • salt & pepper to taste


  • Place peeled & cut potatoes into a large pot of cold water. Add thyme, garlic, bay leaf and salt. Bring to a boil over high heat, then reduce heat to medium-high and continue cooking until just *fork tender.
    *fork tender is when you can insert a fork easily into a potato and lift it slightly out of the water before it falls off fork.
  • Once potatoes are fork tender, drain and return to cooking pot to continue to dry. Using a potato masher or potato ricer mash potatoes.
  • Add butter, cream cheese, sour cream and milk and continue to mash until smooth and creamy. Season with salt & pepper to taste. Transfer potatoes to a 9x13 casserole dish. Cover and refrigerate for up to 2 days.

Oven Reheating Method

  • Remove casserole from refrigerator and allow to rest while oven is preheating. Preheat oven to 350° F. Bake casserole uncovered for about 45 minutes, until top is lightly golden brown and potatoes are hot. Tent with aluminum foil during cooking if browning too quickly.

Microwave Reheating Method

  • Uncover casserole and microwave on high for one minute intervals. Stir after each additional minute, until potatoes are hot.