- 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
Preheat the oven to 325 degrees F. Butter a 12-cup bundt pan with 1 teaspoon of the butter and set aside.
In a large bowl using an electric mixer, cream the butter, brown sugar, and sugar. Add the sweet potatoes and beat until light and fluffy. Add the eggs one at a time, and beat after each addition.
Into a bowl, sift together the flour, soda, powder, salt, cinnamon, ginger, allspice, and nutmeg. Add to the sweet potato mixture a third at a time. Fold in the nuts and vanilla. Pour into the prepared pan and bake until a tester inserted into the center comes out clean, about 1 hour to 1 hour and 10 minutes. Remove from the oven and let cool for 10 minutes in the pan.
While the cake is resting in the pan, in a bowl, combine the confectioners' sugar, orange juice, and orange zest. Stir well to combine and make a tight glaze, adding more orange juice 1/2 teaspoon at a time to achieve a pourable consistency.
Turn out onto a wire rack. While the cake is still warm, drizzle the orange-sugar glaze to evenly coat. Cool completely before cutting.