In a bowl mix to the eggs with the sugar until white. Add poppy seeds and lemon rind. Flour mixed with baking powder, vanilla and salt alternately with milk add 3 times to egg mixture, stirring by hand. In the end, add the oil and melted (not hot) butter. Pour the mixture into littered with paper tray. Bake in a preheated 180C oven for 40 minutes. Can be checked with a toothpick - should come out dry. The cake is removed from the tray when it is completely cool and sprinkle with powdered sugar. * tray size 24-26 cm.