INGREDIENTS
- 1/2 cup plus 1 tbsp butter, plus extra for the pan, at room temperature
- 4 firm ripe plums, each cut into 8 wedges
- 1/4 cup plus 2/3 cup granulated sugar
- 1 cup all-purpose flour
- 3/4 tsp baking powder
- 1/4 tsp baking soda
- 1/4 tsp kosher salt
- 1 large egg
- 2/3 cup sour cream
- 1 tsp pure vanilla extract
DIRECTIONS
- Preheat oven to 350 degrees.
- Butter an 8-inch cake pan and line the bottom with parchment paper.
- Melt 1 tbsp of the butter in a large skillet over medium-high heat. Add the plums and 1/4 cup of the sugar and cook, tossing until the sugar dissolves and the juices from the plums become syrupy, 3 to 4 minutes. Arrange the plums in the cake pan in slightly overlapping concentric circles, starting from the outside. Spoon any pan juices over the top.
- In a small bowl, whisk together the flour, baking powder, baking soda, and salt.
- With an electric mixer, beat the remaining 1/2 cup of the butter and 2/3 cup of the sugar until fluffy. Beat in th egg, sour cream, and vanilla. Gradully add the flour mixture, mixing just until incorporated.
- Pour the batter over the plums and bake until a toothpick inserted in the center comes out clean, 50 to 55 minutes. Let cool in the pan for 1 hour. Place a large plate over the cake pan and invert the cake onto the plate.