This is a Dutch buttercake.
1 Preheat oven to 350 degrees F (175 degrees C). Grease and flour one 10 inch loaf pan.
2 Mix grated lemon rind with 1 tablespoon sugar.
3 Beat butter and sugar with vanilla sugar and lemon rind until the mixture becomes white and fluffy. Add eggs one at a time mixing after each one.
4 Mix flour and baking powder together and then carefully fold into the butter and egg mixture. Pour batter into prepared loaf pan.
5 Bake cake for 60 to 75 minutes or until a knife inserted in the middle comes out clean.