Upside-Down Plum Cake

Thank you to our lovely friend Shar for the abundance of sweet plums from her tree.  We made this delicious upside-down plum cake, which is the perfect way to put them to good use!

Ingredients

• 10 tablespoons (1 1/4 sticks) unsalted butter, room temperature, plus more for pan
• 1/3 cup packed light-brown sugar
• 6 medium plums, halved and pitted
• 1/2 pint raspberries
• 1 1/2 cups all-purpose flour
• 1 teaspoon ground cinnamon
• 3/4 teaspoon baking powder
• 1/4 teaspoon baking soda
• 1/4 teaspoon salt
• 1/4 teaspoon grated nutmeg
• 3/4 cup granulated sugar
• 1 teaspoon pure vanilla extract
• 3 large egg yolks
• 1/2 cup sour cream

Method

1. Preheat oven to 180 degrees. Butter a round a springform pan; line with parchment paper. Melt 2 tablespoons butter; pour into pan. Using a sieve, sprinkle light-brown sugar evenly over the melted butter. Arrange plum halves cut side down on top of the brown sugar, squeezing in as many plums as possible to allow for shrinkage during baking.
2. Sift together the flour, cinnamon, baking powder, baking soda, salt, and nutmeg; set aside. In an electric mixer fitted with the paddle attachment, cream the remaining 8 tablespoons butter and the sugar until light. Beat in the vanilla extract. Add the egg yolks, one at a time, beating well after each addition. Add half the flour mixture, and beat until combined. Beat in the sour cream. Beat in the remaining flour mixture.
3. Spoon cake batter on top of plums, spreading evenly with a small spatula. Place the pan on a rimmed baking sheet to catch any juices; transfer to the oven, and bake until a cake tester inserted into the cake comes out clean, 60 minutes. Transfer to a wire rack to cool, about 1 hour. Run a knife around edge of pan to loosen cake. Remove ring; invert onto a serving plate. Serve slightly warm or at room temperature.