Kumquat Upside-Down Cake
Servings: Makes one 9-inch cake
3 tablespoons unsalted butter
⅓ cup (71g) light brown sugar
About 35 (665g) kumquats, halved
16 tablespoons (226g) unsalted butter, softened
½ cup (99g) granulated sugar
½ cup (106g) light brown sugar
2 large (113g) eggs
1 teaspoon pure vanilla extract
2 cups (240g) all-purpose flour
1 teaspoon ground cinnamon
½ teaspoon ground ginger
1 teaspoon baking powder
½ teaspoon baking soda
¾ teaspoon fine sea salt
1½ cups (360g) sour cream
Whipped Cream (optional)
1 cup (235g) cold heavy cream
¼ cup (50g) granulated sugar
¾ teaspoon ground cinnamon
¼ teaspoon ground ginger
¼ teaspoon ground cloves
1. Make the topping: Preheat the oven to 350°F. Grease a 9-inch cake pan thoroughly with butter, being especially generous when coating the base of the pan.
2. Sprinkle the brown sugar evenly over the base of the pan. Arrange the kumquats, cut-side down, in the prepared pan, packing them in tightly so the whole base is fully covered.
3. Make the Batter: In the bowl of an electric mixer fitted with the paddle attachment, cream the butter, sugar and brown sugar until light and fluffy, about 5 minutes.
4. Add the eggs one at a time, mixing well to combine. Add the vanilla extract and mix to combine.
5. Add the flour, cinnamon, ginger, baking powder, baking soda and salt; mix to combine.
6. Add the sour cream and mix well to combine. Pour the batter over the prepared citrus slices and gently spread into an even layer.
7. Bake until a toothpick inserted into the center comes out clean, 40 to 45 minutes. Cool for 10 minutes inside the pan before inverting onto a cooling rack to cool completely.
8. Make the whipped cream (optional): If using, make the whipped topping while the cake cools. In the bowl of an electric mixer fitted with the whisk attachment, whip the cream, sugar, cinnamon, ginger and cloves to soft peaks. Keep the whipped cream refrigerated until ready to serve.