Ingredients

· ¾ cup unsalted butter, room temperature, plus more for pan

· 1½ cups plus 2tbsp all-purpose flour (spooned

and levelled)

· ½ tsp baking soda

· ¼ tsp salt

· ½ cup packed light-brown sugar

· ½ cup granulated sugar

· 3 large eggs

· 1tsp pure vanilla extract

· 2tsp finely grated lemon zest

· ¼ cup sour cream

· 3 plums, halved, pitted, and cut into eighths

· Powdered sugar for dusting

Method

Preheat oven to 180 degrees. Butter an 8-by-2-inch or a 9-inch cake pan and line bottom with a round of parchment. In a large bowl, whisk together 1½ cups of flour, baking soda, and salt. Using an electric mixer, beat butter and sugar together until light and fluffy. With mixer on low, beat in eggs, one at a time, until incorporated; beat in vanilla and lemon zest. Beat in half the flour mixture and sour cream. Add remaining flour mixture; mix just until combined. Spread batter into pan and smooth top with a knife. In a bowl, toss plums with two tablespoons flour and sprinkle over batter. Bake until cake is golden, about 30 minutes; loosely tent with foil and bake until cake pulls away from side of pan and a cake tester inserted in center comes out clean, about 35 minutes more. Let cake cool completely in pan. Run knife around cake edge and remove cake from pan. Dust with confectioners' sugar before serving.