Sweet potato spice cake and the first day of fall! vote now OtherVery Easy1 h 25 m Send this recipe to a friend Print this page Ask a question to the author Post your photo of this recipe Ingredients 5 1 teaspoon unsalted butter at room temperature, plus 1/2 pound (2 sticks) 1 cup packed light brown sugar 1 cup granulated sugar 2 cups mashed cooked sweet potatoes (about 2 pounds raw sweet potatoes) 4 large eggs 3 cups all-purpose flour 1 teaspoon baking soda 1 teaspoon baking powder 1/2 teaspoon salt 1 teaspoon ground cinnamon 1 teaspoon ground ginger 1/2 teaspoon allspice 1/4 teaspoon grated nutmeg 1 cup chopped toasted walnuts 1 teaspoon vanilla extract 1 1/2 cups confectioners' sugar 2 tablespoons fresh orange juice, or slightly more as needed 1 teaspoon grated orange zest View the directions