Ingredients:
Wheat flour 300 gr
Butter 100 gr
Baking powder 1/2 teaspoon
Sour cream or yogurt 100 gr
Egg yolk 1 pc
Vanilla sugar 1 teaspoon or vanillin 1/2 teaspoon

Filling:
Walnut 150 gr
Condensed milk, 3 tablespoons or any jam of your choice and 2 tablespoons sugar

Bake at 180℃ for 30 minutes