Go Back
Kima

Twice Baked Mashed Potato Casserole

This Twice Baked Mashed Potato Casserole is rich, creamy, cheesy, and full of garlic flavor. Made with fluffy mashed potatoes, cream cheese, Parmesan, cheddar, Dijon mustard, and a golden cheesy topping, it is an easy gluten-free side dish for holidays, family dinners, or special occasions.
Print Recipe Pin Recipe
Prep Time 15 minutes
Cook Time 35 minutes
Total Time 50 minutes
Servings: 6 servings
Course: Side Dish
Cuisine: American
Calories: 361
Ingredients Equipment Method Notes

Ingredients
  

Cheesy Garlic Mash
  • 2 pounds potatoes Russet or Yukon Gold, peeled and cut into chunks
  • 4 tablespoons salted butter 1/2 stick
  • 1/2 cup cream cheese 125g
  • 1/3 cup milk 80ml
  • 1 tablespoon garlic powder
  • 1/2 tablespoon Dijon mustard
  • 1/4 cup Parmesan cheese about 4 tablespoons, grated
  • 1/4 teaspoon salt plus more for boiling the potatoes if needed
  • 1 pinch black pepper
  • 1/2 cup cheddar cheese 60g, shredded
Mashed Potato Casserole Topping
  • 1 tablespoon salted butter cut into small pieces
  • 2 tablespoons Parmesan cheese grated
  • 1/4 cup cheddar cheese 30g, about 4 tablespoons, shredded

Equipment

  • Large pot
  • Potato masher
  • Whisk
  • 9-inch oval baking dish

Method
 

Make the Cheesy Garlic Mash
  1. Peel the potatoes and cut them into evenly sized chunks.
  2. Place the potatoes in a large pot of cold salted water and bring to a boil.
  3. Boil for 10–15 minutes, or until the potatoes are fork-tender but not falling apart.
  4. Drain the potatoes well and set them aside.
  5. Reduce the stovetop heat to low.
  6. To the empty pot, add the butter, cream cheese, milk, garlic powder, Dijon mustard, Parmesan, salt, and black pepper.
  7. Place the pot over low heat and whisk until the ingredients melt together into a smooth, creamy sauce.
  8. Add the cooked potatoes back to the pot along with the shredded cheddar cheese.
  9. Mash gently until smooth and creamy. Taste and adjust the salt and pepper as needed, taking care not to overwork the potatoes.
Make the Mashed Potato Casserole
  1. Preheat the oven to 350°F (180°C).
  2. Spoon the mashed potatoes evenly into a 9-inch oval oven-safe baking dish and smooth the top.
  3. Dot the top with the remaining tablespoon of butter, sprinkle evenly with Parmesan, then finish with the shredded cheddar cheese.
  4. Once the oven is fully preheated, bake uncovered for 20 minutes, or until heated through.
  5. Move the casserole under the broiler and broil for about 5 minutes, or until the cheese is melted, bubbling, and golden brown. Watch closely to prevent burning.
  6. Remove from the oven and serve warm.

Notes

Take care not to overwork the mashed potatoes, as excessive mixing can overdevelop the starch and create a gluey texture.
Taste and adjust the seasoning before transferring the mashed potatoes to the casserole dish.
For the best results, bake the casserole only after the oven is fully preheated.
Keep a close eye on the casserole while broiling, as the cheese can brown quickly.