Citrus Upside-Down Cake
Pastry chef Karen Damasco shared her recipe with Martha on Martha Bakes episode 401.
- Yield: Makes one 8-inch cake
Photography: Bryan Gardner
Source: Martha Bakes
- 2 small oranges
- 1 medium Ruby Red grapefruit
- 10 kumquats
- 3/4 cup packed light-brown sugar
- 3 tablespoons unsalted butter, plus more for pan
- 1/2 cup (1 stick) unsalted butter, room temperature
- 1/3 cup packed light-brown sugar
- 1/3 cup granulated sugar
- Finely grated zest of 1 lemon
- Finely grated zest of 1 orange
- 1 large egg
- 1 large egg yolk
- 1 1/2 cups cake flour (not self-rising)
- 1 teaspoon baking powder
- 1 teaspoon freshly grated nutmeg
- 3/4 teaspoon coarse salt
- 1/2 teaspoon baking soda
- 3/4 cup whole milk
- 3 tablespoons sour cream
- 1 tablespoon fresh lemon juice
Preheat the oven to 350 degrees and position a rack in the center of the oven.
Topping: Butter an 8-inch round cake pan and line with parchment. With a sharp paring knife, slice ends of oranges and grapefruit. Following curve of fruit, cut away peel, removing as much white pith as possible. Slice oranges and grapefruit crosswise into 1/4-inch-thick rounds and remove any seeds; set aside. Slice kumquats into 1/4-inch-thick rounds and remove any seeds; set aside. Place brown sugar in medium bowl. Melt butter and pour over brown sugar, whisking to combine. Spread mixture over bottom of prepared pan. Arrange sliced citrus over the sugar mixture in pan; set aside.
Cake: In the bowl of electric mixer fitted with a paddle attachment, beat butter, sugars, and zests until pale and fluffy, 3 to 5 minutes, scraping down the sides of the bowl as needed.
Add egg; beat until well combined. Add egg yolk; beat until light and fluffy.
In a large mixing bowl, whisk together flour, baking powder, nutmeg, salt, and baking soda.
In a medium bowl, combine milk, sour cream, and lemon juice.
Add the flour mixture in three additions, alternating with the milk mixture, beginning and ending with the flour mixture. Transfer batter to prepared pan; place pan on a rimmed baking sheet. Bake until cake springs back in the center and a cake tester comes out clean, 50 to 60 minutes.
Transfer pan to a wire rack for 15 minutes. Trim top of cake using a serrated knife to create a level surface. Run a knife around edge of cake to loosen, then carefully invert onto a platter. Serve warm or at room temperature.