Open and drain both can of the Plums. Cut plums in halve and set aside.
Preheat the oven to 350°
Butter a 9-inch round springform or cake pan with high sides (shorter sided pans will over flow), line the bottom with waxed or parchment paper, butter the paper, then dust lightly with flour.
Beat the butter and sugar until light then incorporate the eggs. Then beat in the buttermilk or yogurt, vanilla, and grated rind of the lemon.
Mix the flour, baking powder, salt, and baking soda together. Then slowly mix into the wet ingredients until fully mixed together.
Spoon half of the batter into the cake pan. Cover with half of the plums, cut side down. Then spoon the remainder of the batter over the plums. Cover with the remaining plum halves, this time cut side up.
Bake for 50 minutes. The cake should be firm, golden and pulling away from the sides of the pan.
Cool for 15 minutes, then invert onto a plate, peel off the parchment paper, and invert again onto another plate.
In a small mixing bowl add whipping cream, sugar and vanilla. Beat until you get soft peaks.
Serve warm at room temperature with a dollop of whipping cream