Sweet Potato Cake with Coffee-Tahini Icing
Sweet potatoes and spices are a traditional autumn combo, but the coffee-tahini icing gives a middle eastern twist to these familiar ingredients, making a simple one-layer cake into a treat fit for any celebration. However, you can also skip the icing and simply sprinkle the cake with a little powdered sugar for a more casual dessert.
Equipment
- electric mixer
Ingredients
- 2 sweet potatoes about 1-1/4 pounds total
Dry Ingredients
- 2 cups all-purpose flour
- 2 teaspoons baking powder
- 1 teaspoon ground cinnamon
- ¾ teaspoon baking soda
- ½ teaspoon ground ginger
- ½ teaspoon salt
- 1/8 teaspoon ground nutmeg
.
- ½ cup unsalted butter, softened (1 stick)
- ½ cup firmly packed light brown sugar
- ½ cup sugar
- 2 eggs
- ¾ buttermilk
Coffee-Tahini Icing
- ½ cup mascarpone or cream cheese, softened
- 1/4 cup unsalted butter, softened (½ stick)
- ¾ cup powdered sugar, sifted
- ¼ teaspoon espresso instant coffee dissolved in ¼ teaspoon warm water
- 2 tablespoons tahini
- 1/8 teaspoon salt
- Toasted sesame seeds for garnish, optional
Instructions
- Preheat oven to 400ºF. Pierce sweet potatoes in several places with sharp knife or fork and place on a rimmed baking sheet. Bake potatoes in center of oven until a knife easily penetrates the flesh, 50 to 75 minutes, depending on size of potatoes. Cool potatoes until able to handle, cut in half and scoop out flesh. Mash sweet potato flesh with a fork and cool completely. You will need 1-1/2 cups mashed sweet potato; reserve any additional for another use.
- Reduce oven temperature to 350ºF. Butter and flour a 9 by 2-inch round cake pan; set aside.
- Combine dry ingredients in a medium bowl; set aside.
- Beat butter and sugars in a large bowl with an electric mixer on medium speed until light and creamy, 2 to 3 minutes, scraping down the sides of the bowl as necessary. Add eggs one at a time, beating on medium speed until well combined. Add 1-1/2 cups mashed sweet potato and beat on medium speed until light and fluffy, about 1 minute. Scrape down sides of bowl and add half the dry ingredients; mix on low speed just until incorporated, about 20 seconds. Add buttermilk and beat on low speed until blended and then add the remaining dry ingredients, mixing just until combined. Stir in any visible flour mixture by hand with a spatula. Scrape batter into prepared cake pan, smoothing the surface. Batter will be thick.
- Bake cake in the center of the 350ºF oven until a toothpick inserted into the center comes out clean, 50 to 55 minutes. Remove to a cooling grid and let cool until able to handle pan, 20 to 30 minutes. Loosen edges of cake from the sides of the pan with thin knife and invert cake onto a cooling grid, tapping pan as necessary to release the cake. Invert cake so top is up and cool completely.
- To make icing: Make sure the butter and mascarpone or cream cheese are equally softened (about room temperature) and beat in a bowl with an electric mixer on medium speed until fluffy, about 30 seconds. Gradually beat in powdered sugar, mixing on low speed. Add dissolved instant espresso and mix on medium speed until combined, then add tahini and salt and beat just until smooth.
- Spread icing on top of cooled cake and sprinkle with toasted sesame seeds, if desired. Cut cake into wedges to serve. Store any leftovers, well wrapped, in refrigerator.
- Makes 12 to 16 servings.