The wispy peaks and valleys of the homemade fluff give this side dish drama and intrigue that mini marshmallows (which is our traditional topping) just can’t. If you already have a favorite recipe for the base of the casserole, you can swap that in for mine here and just top your classic with the brown sugar fluff. —Ashley Rodriguez
- Serves 8 to 10
stick butter, softened
plus 2/3 cup dark brown sugar, divided
plus 1/4 teaspoon salt, divided
- Preheat your oven to 400° F. Place the yams on a baking sheet and roast in the oven until very tender, about 1 hour. Let cool, then remove skin with a paring knife. Cut yams into 1-inch chunks and place in the bowl of a food processor.
- Process the yams until a smooth purée forms. To that, add the butter, 1/4 cup brown sugar, 1/2 teaspoon salt, cinnamon, and a few grinds of pepper. Pulse that together, then taste and adjust the seasoning.
- Add the milk and the 2 whole eggs and process until smooth. Transfer the mixture to a baking dish.
- Bake for 30 to 40 minutes, until slightly puffed.
- For the marshmallow fluff: Make a double boiler by bringing a small pot of water to a simmer, then placing the bowl of your stand mixer or another large stainless steel bowl atop the water.
- Add the 3 egg whites, remaining 2/3 cup brown sugar, and remaining 1/4 teaspoon salt and whisk continuously until the sugar dissolves and the liquid is warm to the touch.
- Transfer the bowl from the stovetop to your stand mixer and use the whisk attachment to whip the whites on medium-high speed until it turns glossy with stiff peaks, about 5 to 8 minutes. (Use a hand-held mixer if you do not have a stand mixer.)
- Once the casserole has finished baking, use a rubber spatula to cover the yam mixture with the fluff. Use the back of the spatula create dramatic peaks. This will give you a nice variation in color and texture once the dish is baked.
- Return to the oven for 5 to 7 minutes, or until the marshmallow fluff starts to turn golden and the fluffy peaks are just shy of burnt.