Preparation Preheat oven to 350°F. Butter 9-inch-diameter springform pan. Whisk first 3 ingredients in small bowl to blend. Using electric mixer, beat butter in large bowl until fluffy. Beat in 3/4 cup sugar. Add eggs 1 at a time, then lemon juice and lemon peel, beating until blended after each addition. Beat in flour mixture. Spread batter in prepared pan. Press plum wedges halfway into batter in concentric circles, spacing slightly apart. Mix remaining 1 1/2 tablespoons sugar and cinnamon in small bowl; sprinkle over plums. Bake until cake is browned on top and tester inserted into center comes out clean, about 50 minutes. Cut around cake; release pan sides. Serve cake warm or at room temperature.
Preparation Preheat oven to 350°F. Butter 9-inch-diameter springform pan. Whisk first 3 ingredients in small bowl to blend. Using electric mixer, beat butter in large bowl until fluffy. Beat in 3/4 cup sugar. Add eggs 1 at a time, then lemon juice and lemon peel, beating until blended after each addition. Beat in flour mixture. Spread batter in prepared pan. Press plum wedges halfway into batter in concentric circles, spacing slightly apart. Mix remaining 1 1/2 tablespoons sugar and cinnamon in small bowl; sprinkle over plums. Bake until cake is browned on top and tester inserted into center comes out clean, about 50 minutes. Cut around cake; release pan sides. Serve cake warm or at room temperature.