Stir sugar, oil, yolks, cream until fluffy.
Mix in water, snow and flour with baking powder.
Pour the dough onto a baking sheet or into a larger baking pan.
For the filling, mix curd, sugar, egg and sour cream until smooth.
Pipe the mixture onto the dough in a lattice shape.
Bake at approx. 185 °C (top and bottom heat) until golden brown.
When cooled, sprinkle with powdered sugar.