Creamy baked sweet potatoes mashed with butter and brown sugar, topped with toasted homemade marshmallow fluff or classic marshmallows. No peeling, no boiling, no eggs.
Preheat the oven to 425°F. Line a baking sheet with foil.
Place the 5 large sweet potatoes on the baking sheet and bake until extra soft, about 1 hour.
Cut them open and scoop the sweet potato into a large bowl, leaving the skins behind.
While hot, mash with 1/4 cup unsalted butter, 1/2 cup brown sugar, 1/2 tsp salt, 1 tsp vanilla extract and 2 tbsp heavy cream until smooth or the texture you like. An electric mixer or blender makes it extra smooth.
Spread the mashed sweet potatoes into a 9x13-inch casserole dish (a smaller dish works too; the layer will just be thicker).
For the fluff topping: spread homemade marshmallow fluff over the hot casserole and toast it with a kitchen torch until golden.
For the marshmallow topping: reduce the oven to 350°F, cover the casserole with 10 large marshmallows and bake for 5 to 10 minutes, watching closely, until puffed and golden.
Notes
Make-ahead: Leave the topping off, cover, and refrigerate for up to 2 days. Reheat in a 325°F oven, covered with aluminum foil, for 15 to 25 minutes.
Marshmallow fluff: Make it a few days ahead. The recipe is here.
Leftovers: Store in an airtight container in the fridge for up to 3 days. Reheat in the oven.
Freezing: Sweet potato casserole freezes well for up to two months. Freeze it before adding the topping. Thaw it overnight in the fridge before adding the topping and reheating in the oven.