Sweet Potato Cranberry Gratin is the kind of elegant, festive, sweet-savory side dish that makes holiday tables unforgettable. It layers tender roasted sweet potatoes with bright pops of cranberry, warm spices, and a luscious cream mixture that bakes into a silky, caramelized sauce. Every bite blends comforting sweetness, creamy texture, and tart juicy bursts that keep the dish vibrant instead of heavy.
Whether served at Thanksgiving, Christmas, or any cozy autumn meal, this gratin brings beautiful color, incredible aroma, and a gourmet touch with almost no effort. It’s easy to assemble, perfect for making ahead, and pairs flawlessly with both savory meats and plant-based mains. Serve it once and it instantly becomes a signature seasonal favorite.
Equipment You Will Need
- 9×13-inch baking dish
- Mixing bowls
- Chef’s knife
- Cutting board
- Whisk
- Rubber spatula
- Aluminum foil
- Measuring cups and spoons
- Oven mitts
Ingredients List
- 4 large sweet potatoes, peeled and thinly sliced
- 1 ½ cups fresh or frozen cranberries
- 1 cup heavy cream
- ½ cup milk
- 3 tbsp melted butter
- ⅓ cup brown sugar
- 1 tsp cinnamon
- ½ tsp nutmeg
- ½ tsp ground ginger
- ½ tsp salt
- ¼ tsp pepper
- 1 tsp vanilla extract
- Optional additions: ½ cup chopped pecans, orange zest, maple syrup drizzle
Step-by-Step Instructions
Begin by preheating your oven to 375°F (190°C). Peel the sweet potatoes and slice them into thin, even rounds—about ⅛-inch thick—to ensure uniform cooking. Place the slices in a large bowl and gently toss with a pinch of salt and pepper.
Grease your baking dish lightly with butter and arrange a layer of sweet potato slices across the bottom, overlapping them slightly so the gratin holds together beautifully. Sprinkle a handful of cranberries over the layer.
In a mixing bowl, whisk together the heavy cream, milk, melted butter, brown sugar, cinnamon, nutmeg, ginger, vanilla, salt, and pepper until smooth. Pour a small amount of this mixture over the first layer of potatoes and cranberries.
Continue layering potatoes and cranberries, pouring cream mixture over each layer until all ingredients are used. Gently press the layers down with your hands or spatula to help the cream seep through every part of the dish.
Cover the baking dish tightly with foil and bake for about 40 minutes. Remove the foil and continue baking another 20–25 minutes or until the top begins to brown slightly and the potatoes are fork-tender.
If the top browns too quickly, tent loosely with foil. Let the gratin rest for 10 minutes before serving; this helps the creamy sauce thicken and ensures cleaner slices. Serve warm as a stunning, aromatic side dish.
Expert Tips for Success
Using a mandoline slicer ensures consistent thin slices that cook evenly and create a beautifully layered gratin. Don’t skip overlapping the slices—it gives the dish structure and a more impressive presentation once sliced.
Make sure cranberries are distributed evenly throughout; clusters can create pockets of extreme tartness instead of balanced bites. Whisk the cream mixture thoroughly so every bit of sugar and spice dissolves properly, avoiding uneven sweet spots.
Covering early in the baking process steams the potatoes gently, creating softness before browning the top. Allowing the dish to rest is crucial; the creamy sauce needs cooling time to thicken and cling to the layers.
If you want a caramelized top, broil for the last one to two minutes while watching closely. Taste the cream mixture before pouring—it should taste sweet, warm, and spiced, giving you a preview of the final flavor. Adjust sugar or spice levels according to preference before assembling.
Variations and Substitutions
For deeper caramel notes, replace part of the brown sugar with maple syrup or add a drizzle on top before baking. A pecan-cranberry version includes chopped pecans between layers for extra crunch and nutty richness.
For a savory-leaning twist, reduce the sugar slightly and add a sprinkle of dried thyme or rosemary. If you prefer a richer texture, swap milk for half-and-half or add a tablespoon of cream cheese to the mixture.
Create a citrus-forward variation by adding orange zest to the cream mixture—it brightens the cranberries beautifully. Substitute heavy cream with coconut milk for a dairy-free option; its natural sweetness pairs wonderfully with sweet potatoes.
For a more dessert-leaning gratin, add mini marshmallows during the last five minutes of baking. If you want a lighter dish, use evaporated milk instead of cream while keeping the overall texture silky.
Serving Suggestions and Pairings
Serve this gratin alongside holiday mains like roasted turkey, ham, glazed chicken, or herb-crusted pork. It also pairs beautifully with vegetarian dishes like lentil loaf, stuffed squash, or mushroom Wellington.
Add a fresh contrast with green beans, roasted Brussels sprouts, or a crisp apple-pecan salad. For a full autumn feast, serve with cornbread, cran-orange relish, and savory stuffing.
For everyday meals, pair with baked chicken thighs, seared salmon, or grilled sausages. It makes an excellent potluck dish due to its vibrant presentation and reheating versatility. When serving, garnish with fresh thyme, orange zest, or a sprinkle of pecans for visual impact.
A drizzle of warm maple syrup just before serving adds shine and depth. Its sweet-savory balance makes it a perfect complement to both hearty and lighter dishes.
Storage, Freezing, and Reheating
Store leftovers covered in the refrigerator for up to four days. Reheat in the oven at 325°F (160°C) until warmed through for best texture.
Microwaving works but may soften the top; reheat in short bursts to avoid overcooking. If the gratin thickens too much after chilling, add a splash of milk or cream before reheating to restore silkiness.
To freeze, allow the baked gratin to cool completely. Wrap tightly in plastic wrap and foil or freeze portions separately for easier thawing. Store for up to two months. Thaw overnight in the refrigerator before reheating.
For reheating from frozen, bake covered at 325°F until hot, then uncover briefly to restore the caramelized top. The dish maintains great flavor after freezing, though the texture may soften slightly.
Frequently Asked Questions
Can I prepare it ahead of time?
Yes—assemble up to 24 hours in advance, refrigerate, then bake fresh.
Can I use canned cranberries?
Fresh or frozen cranberries work best; canned sauce is too soft for layering.
Do I need to par-cook the sweet potatoes?
No—thin slices cook fully during baking.
Can I make it less sweet?
Absolutely—cut the sugar in half and skip the vanilla.
Can I add cheese?
Yes—gruyère or Parmesan adds a savory layer that pairs beautifully with sweet potatoes.
