Step 1

Preheat oven to 350°F. Coat a 9-inch springform pan with baking spray; set aside. Slice plums in half lengthwise; remove and discard pits. Cut each half lengthwise into 6 slices (about ½-inch thick each). Set aside.

Step 2

Beat butter and 1 cup of the sugar with a stand mixer fitted with a paddle attachment on medium speed until light and fluffy, 2 to 3 minutes. Add eggs 1 at a time, beating just until combined. Whisk together flour, cornmeal, baking powder, salt, and ½ teaspoon of the cinnamon in a medium bowl until thoroughly combined. Gradually add flour mixture to butter mixture, beating on low speed, until just combined, about 1 minute. Spoon mixture into prepared springform pan, and spread evenly.

Step 3

Arrange plum slices around pan edge and in center of pan, overlapping slices slightly. Stir together remaining 1 tablespoon sugar and ¼ teaspoon cinnamon in a small bowl; sprinkle evenly over torte.

Step 4

Bake in preheated oven until a wooden pick inserted in center of torte comes out clean, 50 minutes to 1 hour. Let torte cool in pan until just slightly warm, about 1 hour. Remove sides from springform pan. Serve torte while slightly warm, or let cool to room temperature.