This post may contain affiliate links. Please see our disclosure policy.
Creamy, fluffy, and full of flavor, this Mashed Potato Casserole is the perfect way to prepare mashed potatoes for a gathering or the holidays. It's rich, buttery, and delivers the same comforting mashed-potato flavor in a convenient make-ahead version that lets you actually enjoy your meal.
Why This Mashed Potato Casserole Works
This recipe comes from my husband's family, and it's a must-make holiday side. My mother-in-law graciously shared her recipe for what she calls Holiday Potatoes, and the name fits for many reasons!
- Rich, but EASY. It's creamy and decadent, yet simple to make. And when it comes to entertaining, especially during the holidays, easy is a must.
- Make it up to 2 days ahead. Assemble it, refrigerate, and bake right before serving, instead of mashing potatoes while your guests arrive. It's one of the easiest make-ahead holiday dishes to get a head start on.
- It travels well. You can bake it at home and it will keep warm for about an hour, or assemble it in advance and bake it when you arrive, making it a great potluck dish.
- It puffs up in the oven. The eggs help it bake up light, with slightly browned edges, so it feels special enough for a holiday table.
5-Star Reader Review
This was very easy to make and a big crowd pleaser! I especially liked being able to make it the evening before. Has been added to our favorites list! -Lana ⭐⭐⭐⭐⭐
Notes on Ingredients
- Potatoes: Use Yukon gold or russet potatoes. They're starchy, so they mash up smooth and soak up the butter. Waxy potatoes, like red potatoes, can turn gummy.
- Cream cheese and sour cream: Full-fat sour cream and a softened block of full-fat cream cheese give this casserole its rich, creamy texture. Lower-fat versions just don't hold up the same way.
- Butter and milk: Melted unsalted butter for flavor, plus milk of any fat percentage to loosen the potatoes.
- Onion: Finely chopped yellow onion adds a little savory flavor. It's optional.
- Eggs: They help the casserole puff up as it bakes.
Dietary Swaps & Variations
- Cheesy: Stir 1 cup of shredded cheddar into the potato mixture, then top the casserole with another cup of cheese before baking.
- Loaded: Top with cheese and up to ½ cup of crumbled cooked bacon before baking. Add chopped chives right before serving.
- Egg-free: Simply omit the eggs. The casserole won't puff up as much, but it will still taste rich and creamy.
- No onion: Leave it out, or replace the chopped onion with 2 teaspoons of onion powder.
- Gluten-free: This casserole is naturally gluten-free. If you're cooking for someone with celiac disease, check the labels on the dairy, especially if you use flavored or reduced-fat versions.
How to Make Mashed Potato Casserole
I'll walk you through each step below, whether you're a seasoned cook or making this for the first time. The recipe card at the bottom of the post has the full quantities and a video.
- Boil the potatoes. Peel and cut the potatoes into even chunks, then place them in a large pot. Cover with cold water and add the salt. Bring to a boil, then reduce the heat to medium and simmer until fork-tender, about 15 to 20 minutes. Starting in cold, well-salted water helps the potatoes cook evenly and seasons them from the inside out.
- Drain and dry. Drain the potatoes in a large colander, then return them to the hot pot over low heat for 1 to 2 minutes, until all the moisture has evaporated.
Note from Kristen
Don't skip this step! Cooking off the extra moisture keeps your casserole fluffy, not watery.
- Mash by hand. In a large bowl, mash the hot potatoes with a potato masher or ricer until smooth. Skip the hand mixer here. It can make the potatoes gluey.
- Mix in the dairy, then the eggs. Add the softened cream cheese, sour cream, melted butter, milk, chopped onion (if using), salt, and pepper. Mix with a handheld mixer on low speed until combined and fluffy. Whisk the eggs in a small bowl, then add them and mix quickly to combine. Once the potatoes are mashed, a mixer on low won't overwork them. And adding the eggs last gives the potatoes a minute to cool, so the eggs don't scramble.
- Spread it in the dish. Spread the potato mixture into a greased 9x13-inch (3-quart) casserole dish. If you're making it ahead, cover tightly and refrigerate for up to 48 hours. Otherwise, bake right away. Freezing it instead? Mix in an extra ½ cup of milk first (see the make-ahead tips below).
- Bake. Bake at 350℉ for 20 to 25 minutes, until the top is slightly browned and the center is warmed through. If it's been in the fridge, let it sit on the counter for 30 minutes while the oven preheats, then bake uncovered for 45 to 50 minutes. The edges will puff a bit, and your kitchen will smell like buttery heaven.
Serving Suggestions
This mashed potato casserole was made for potlucks and holiday meals.
- For Thanksgiving Dinner: Serve alongside your holiday favorites, like roasted turkey or Instant Pot turkey breast and bread stuffing.
- For Christmas Dinner: Pairs well with Baked Ham, Instant Pot Ham, or a juicy New York Strip Roast.
Make-Ahead Tips
This dish is built for planning ahead and designed to reduce holiday stress!
- Up to 2 Days in Advance: Assemble, cover, and refrigerate. Let it sit at room temperature for 30 minutes while the oven preheats, then bake uncovered at 350℉ for 45 to 50 minutes.
- Up to 1 Month in Advance: Add an extra ½ cup of milk, assemble in a freezer- and oven-safe baking dish (like a disposable foil pan), cover tightly with 2 layers of foil, and freeze for up to 1 month. Thaw overnight in the fridge, let it sit at room temperature for 30 to 60 minutes, then bake at 350℉ for 45 to 50 minutes.
- Traveling? Bake it at home and keep it warm in an insulated casserole carrier, or cover it with foil and wrap it in a warm towel. It will stay warm for about an hour. You can also bake it when you arrive.
Storage & Reheating Tips
- Refrigerate: Store leftovers in an airtight container in the refrigerator for up to 4 days.
- Freeze: For best results, freeze the casserole unbaked (see the make-ahead tips above).
- Reheat: Warm individual servings in the microwave, covered with a damp paper towel so the casserole doesn't dry out.
If you do end up with leftovers, turn them into mashed potato cakes or pierogi lasagna.
More Favorite Holiday Side Dishes
If this casserole is on your holiday menu, round out the table with these:
- Vegan Sweet Potato Casserole: Gluten-free and vegan, so more guests can enjoy it, and it can be made ahead, too.
- Whipped Sweet Potatoes: Roasted sweet potatoes whipped with browned butter and maple.
- Green Bean Casserole: A classic made from scratch, without canned soup.
- Corn Casserole: Rich, slightly sweet, and made without a box.
- Roasted Butternut Squash Salad: A fresh, colorful side that balances out all the rich dishes.
Mashed Potato Casserole
This creamy, make-ahead Mashed Potato Casserole is rich, fluffy, and full of flavor. Perfect for holiday meals or gatherings.
Video
Ingredients
- 3 pounds Russet or Yukon Gold potatoes, peeled and cubed
- 8 ounces full-fat cream cheese, softened
- ¼ cup unsalted butter, melted
- ½ cup full-fat sour cream
- ½ cup milk, any fat percentage
- ½ cup finely chopped yellow onion, optional
- 1 teaspoon kosher salt
- pepper, to taste
- 2 large eggs, lightly beaten
Instructions
- Generously grease a 9x13-inch casserole dish or 3-quart baking dish with butter. Preheat the oven to 350℉ (175℃) if baking immediately.
- Place potatoes into a large stockpot. Cover with cold water and add 2 teaspoons kosher salt. Bring the potatoes to a rapid boil, then reduce the heat to medium. Simmer until the potatoes are fork-tender (the chunks should fall apart easily when pierced with a fork). Drain the potatoes and return to the hot pan. Place over low heat and simmer until all the moisture has evaporated, about 1-2 minutes.
- In a large bowl, mash the hot potatoes by hand with a potato masher.
- Add 8 ounces full-fat cream cheese, ¼ cup unsalted butter, ½ cup full-fat sour cream, ½ cup milk, ½ cup finely chopped yellow onion, 1 teaspoon kosher salt, and a pinch of pepper to the mashed potatoes and mix on low speed using a handheld mixer until combined and fluffy. Whisk 2 large eggs in a small bowl, then add to the potato mixture and mix quickly to combine.
- Transfer the potato mixture to the prepared casserole dish, spreading it out into an even layer. If not baking immediately, cover tightly and refrigerate up to 48 hours.
- If baking immediately, bake at 350℉ (175℃) for 20-25 minutes, or until warmed through and slightly browned. If baking after refrigeration, let the casserole sit at room temperature for 30 minutes while the oven preheats, uncover, and bake at 350℉ (175℃) for 45-50 minutes.
Equipment
- 9x13 Casserole Dish (a beautiful dish for oven to table!)
- large stock pan (this one fits a ton)
- potato masher (or use a potato ricer for less lumps!)
Notes
Egg-Free Option: Simply omit the eggs.
Onions: Feel free to omit the raw onions or replace them with 2 teaspoons of onion powder.
Add Cheese: Stir 1 cup shredded cheddar into the potato mixture and then top the casserole with an additional 1 cup of cheese before baking.
Add Bacon: Before baking, top the potatoes with up to ½ cup crumbled cooked bacon.
Freezing the Casserole: Mix in an extra ½ cup milk, assemble in a freezer and oven safe baking dish (like a disposable foil baking dish), cover tightly with 2 layers of foil, and freeze for up to 1 month. Thaw overnight in the fridge, let sit at room temperature for 30-60 minutes, then bake at 350℉ (175℃) for 45-50 minutes.
Leftovers: Store leftovers in an airtight container in the refrigerator for up to 4 days. Reheat individual servings in the microwave, covered with a damp paper towel so the casserole does not dry out.
Nutrition
Calories: 291kcalCarbohydrates: 34gProtein: 8gFat: 14gSaturated Fat: 8gCholesterol: 79mgSodium: 517mgPotassium: 839mgFiber: 2gSugar: 4gVitamin A: 514IUVitamin C: 10mgCalcium: 106mgIron: 2mg
Nutrition information is automatically calculated, so should only be used as an approximation.
Tried this recipe?Mention @amindfullmom or tag #amindfullmom!
What's the serving size
Hi Kathy! Each serving is about 1/2 cup.
Made this tonight for dinner & It was just really nice. It's simple. It's potatoes, after all, but with a really nice twist. My German husband is "quite fond of potatoes" to say the least, And also very picky.
He was pretty happy when he caught me putting the leftovers into a storage container (I had left the top off on purpose - letting it cool, ya' know, before putting it in the refrigerator 😉), & he was able to snag several extra bites.
I will definitely do these again.
Thank you
B
That is always a win when people are sneaking bites of leftovers 🙂 Thanks for sharing, Betty!
What would be the disadvantage to not using the eggs? Just thinking about omitting them.
Hi Jenn! The casserole won't puff up as much, but it will still taste rich and creamy.
Would it be okay to add bacon bits to this casserole?
Hi Kaye! Before baking, top the potatoes with ½ cup crumbled cooked bacon before baking.