Heat the oven to 180 degrees. Walnut kernels chop, butter melt, add flour, chopped nuts, rushy sugar, vanilla sugar and knead the plastic dough. Place it on a lined baking paper baking sheet and bake in the oven for 25 minutes. Remove the baking sheet from the oven. The temperature decrease to 150 degrees. For the filling, mix the flour with the brown sugar, add one egg, lemon juice and zest. Beat with a mixer until a homogeneous mass.

Received filling cover the cake and put the pan in the oven for another 10-15 minutes so that the mixture is hardened.

Layer the cooled cut into diamonds and serve. Top can be sprinkled with powdered sugar.