Sweet Potato Caramel
Preheat oven to 350 degrees F.Advertisement
For caramel: Combine sweet potato, brown sugar, water, 2 tablespoons butter and salt in an 8-inch glass or ceramic baking dish. Set aside.
To prepare cake: Butter an 8-inch round cake pan, line the bottom with parchment and butter again. Flour the pan and tap out excess.
Whisk buttermilk and vanilla in a small bowl. Combine pastry flour, granulated sugar, baking powder and salt in a stand mixer. Beat on low speed with the paddle attachment until well mixed. Add oil and beat until evenly distributed. With the mixer on, add butter 1 tablespoon at a time and beat until each addition is fully incorporated before adding more. The mixture should look like coarse sand. Add egg and yolk; beat until smooth, scraping down the sides as needed. With the mixer on, add the buttermilk mixture in a slow, steady stream. Beat just until smooth. Pour the batter into the prepared pan and spread evenly.
Place the cake and the reserved sweet potato mixture in the oven. Bake the cake until a tester inserted in the center comes out clean, about 25 minutes. Bake the sweet potato mixture, stirring occasionally, until the sweet potato is tender and the liquid is thick and bubbling, 50 minutes to 1 hour.
Cool the cake in the pan on a wire rack for 10 minutes, then turn out onto the rack. Peel off the parchment, invert and cool completely on the rack, top-side up.
Let the sweet potato mixture cool for 10 minutes. Puree in a blender until smooth. (Use caution when blending hot liquids.) Press the puree through a fine-mesh sieve into a small bowl, then whisk in the remaining 1/2 tablespoon butter until smooth. Spread on top of the cooled cake.
Equipment: 8-inch round cake pan, parchment paper
2 fat, 1 1/2 other carbohydrate, 1 starch