Mix together soft butter, sugar, 3 eggs and lemon juice (creamy white). Sift the flour and mix with the cornstarch, baking powder and lemon zest and stir into the butter mixture spoon by spoon, gradually adding the milk. Put the dough in a loaf pan (or springform pan) that has been greased or lined with baking paper and bake for 40 minutes at 175 degrees (electric stove). Chopstick sample! Cover the still warm cake with the icing or sprinkle with powdered sugar after cooling.
Attention: You only need to buy 2 lemons in total (juice of 2 lemons for the dough and topping, grated zest of 2 lemons for the dough)