Wash the lemon thoroughly and finely grate the peel to prepare lemon zest.
Cream the butter and sugar together until smooth.
Add the eggs and mix well, then add the lemon zest and lemon juice.
Sift the cake flour and baking powder, then add to the mixture and combine.
Shape the dough into rounds and place them on a baking tray.
Bake in a preheated oven at 180°C (356°F) for 15–20 minutes.