Sweet potato casserole is a classic. Here's the best recipe — with or without marshmallows

Robin Miller

Updated November 22, 2023 at 10:48 AM·7 min read

Perfectly smooth, sweet, mashed spuds topped with butter pecan brittle, this rich sweet potato casserole is the ideal side dish for holiday gatherings — no marshmallows required.

But is it a side dish or dessert? Depends on who you ask. I love to serve this sweet potato casserole alongside roasted turkey and chicken, glazed ham and perfectly seared steaks and a sweet counterpoint to the savory meats. But since the flavors are reminiscent of pumpkin or sweet potato pie, it also makes an excellent dessert. When serving as a dessert, I suggest adding a little vanilla ice cream, whipped cream or a drizzle of crème anglaise.

Easy and indulgent, this will be your new, go-to sweet potato casserole recipe. Here are a few tips before you get cooking.

Yams vs sweet potatoes

Do not use yams.

While the terms sweet potato and yam are often used interchangeably, they are different. Sweet potatoes are native to Central and South America and boast orange flesh and thin, reddish-brown skin. True yams are Native to Africa, Asia and the Caribbean and they have starchy white flesh and rough, dark brown skin (like tree bark).

When cooked, sweet potatoes are sweet and creamy, while yams are drier and starchier (more akin to an Idaho spud).

You need about 3 ½ pounds of sweet potatoes for this casserole, which translates to 3 extra-large or 5 to 6 small-to-medium sweet potatoes.

When shopping, grab orange-fleshed sweet potatoes that are free of deep blemishes, bruises and soft spots. I suggest you weigh your sweet potatoes while at the store. The goal is to end up with 4 cups of mashed sweet potatoes for a light, fluffy casserole. Too little mash and the base will be thin; too much mash and the casserole will be overly dense.

How to cook sweet potatoes

Since this casserole calls for mashed sweet potatoes, you need to cook them first. You have two options: roasting and boiling. While both options are fine, I prefer roasting because it produces a deeper, richer flavor.

To roast your sweet potatoes: Scrub the spuds clean and prick all over with a fork or tip of a sharp knife. Set on a baking sheet and roast at 400 degrees F for 45 to 60 minutes or until tender. When cool enough to handle, peel and mash.
To boil your sweet potatoes: Peel and cut into 2-inch chunks (this speeds up cooking time). Transfer the sweet potatoes to a large pot and pour over enough cold water to cover by about 2 inches. Set the pan over high heat and bring to a boil. Boil for 20 minutes or until tender. Drain and mash.

Sweet potato casserole substitutions and omissions

This recipe is forgiving and customizable depending on your dietary preferences.

Eggs: Added for structure; without them we would just have mashed sweet potatoes.

For an egg-free dish, replace the eggs with ½ cup applesauce or 2 flax eggs. To make a flax egg, combine 1 tablespoon of finely ground flaxseed and 3 tablespoons of water; mix well and let stand for 5 to 10 minutes until gelatinous. Note, you will need two flax eggs for this casserole.

Half and half: The combination of milk and cream makes this casserole delightfully creamy. If you have milk and cream, but not half and half, use ¼ cup of each.

For a dairy-free dish, replace the half and half with your favorite dairy-free option, such as oat milk, almond milk or coconut milk. Replace the butter with coconut oil.

For a gluten-free, nut-free topping: Process 1 cup of rolled oats in a blender or food processor until finely ground. Transfer the oat “flour” to a large bowl and add 1 cup rolled oats, ¾ cup brown sugar, ½ teaspoon ground cinnamon and a pinch of salt. Mix well. Fold in 6 tablespoons of melted butter. Use in place of the pecan topping below.

More sides: Love crispy, tender restaurant-style Brussels sprouts? Here's the secret to making them

Sweet potato casserole with marshmallows

For die-hard marshmallow fans, you know who you are, if you’d rather have gooey marshmallows over crunchy pecans, no problem. Simply omit the pecan crumble and sprinkle the top of your casserole with mini marshmallows 10 minutes before baking is complete (after 20 minutes of baking).

How to make sweet potato casserole in advance

Who doesn’t love a make-ahead side dish during the holidays? This casserole is entirely prep-ahead friendly and can be refrigerated or frozen until ready to bake and serve.

Refrigerating: Prepare the sweet potato mixture as instructed and transfer it to your casserole dish. Cover tightly with plastic wrap and refrigerate for up to 5 days.

Prepare the pecan crumble as directed and store it separately, in an airtight container or zip-top bag in the refrigerator for up to 5 days.

When ready to bake, remove the sweet potatoes and pecan topping from the refrigerator 30 minutes before baking. Just before baking, top the sweet potato mixture with the pecan crumble and bake as directed.

Freezing: This sweet potato casserole freezes beautifully. To freeze an unbaked casserole, assemble as instructed, wrap tightly with plastic wrap and then aluminum foil. Freeze for up to 3 months. Thaw overnight in the refrigerator and bring to room temperature before baking.

To freeze a baked casserole, allow it to cool completely before storing. Wrap tightly with plastic wrap and then aluminum foil and freeze for up to 3 months. Thaw overnight in the refrigerator and serve chilled, room temperature or reheated.