Stone and halve the washed plums. Beat the fat and sugar until frothy, stir in the eggs. Mix flour, baking powder and cinnamon, add, add lemon juice. Grease 1/2 a baking sheet, spread the batter on top, cover with the plums. Bake in the preheated oven at 175 ° C for about 50 minutes. Sprinkle flaked almonds on the finished cake.