Cut the plums in half and arrange them on the bottom of a greased tray - diameter 23 cm. Maybe on baking paper. Mess eggs, sugar, flour, the oil and vanilla extract. Pour over the plums with the mixture. Bake at 180C degrees in preheated oven. Bake about 25 minutes, but the best take out only when it obtains a well-baked cake. Once cool turns. Cake becomes slightly juicy, add more flour if you want to get denser.