Beat half amount of the sugar with butter until light. Add in egg york one by one. beat well. Then add in sour cream, milk, vanilla and lemon skin to mix well. Add in cake flour and mix well.

Beat egg white with the remaining sugar until texture form.

Mix both together.

Preheat the oven. Place into it and cook at 160° Celsius (320 ° Fahrenheit) for approx 50 minutes