For the walnut cake, beat margarine, sugar and eggs until thick and fluffy. Heat milk a little and mix in.
Add walnuts, baking powder, vanilla sugar and lemon zest. Gently fold in flour.
Pour the mixture into a greased baking pan and bake in a preheated oven at 180°C for 40 to 45 minutes.
Let the finished walnut cake cool and enjoy.