4 pounds sweet potatoes
6 tablespoons unsalted butter, at room temperature
1/2 cup apple butter
Preheat the oven to 350°. Pierce the sweet potatoes all over with a fork and place on a large rimmed baking sheet. Bake for 1 1/2 hours, or until very tender.
Peel the sweet potatoes and transfer to a large bowl. Mash with a potato masher until creamy, then mash in the butter and apple butter. Season with salt and serve.