For the dough:
450 gram flour
200 gram butter
50 gram sugar
2 gram yeast
pinch of salt
1/4 cup sour cream
For the filling:
300 gram jam (apricot or strawberry)
200 gram ground walnut
100 gram sugar
for the top:
200 gram dark chocolate broken into pieces (chocolate chips)
2 tbsp oil
Mix all the dough ingredients together and knead it well. You should get a firm, not soft, but well shapeable dough. If needed use more yogurt to make the dough softer.
Divide the dough into 3 even pieces.
Grease a 9x11" baking pan, line with wax paper and grease again.
On a floured surface, roll out one of the dough to the size of the baking pan and place it in.
Mix together the ground walnut and sugar.
Put half of the jam on the first layer of dough. Sprinkle the layer of jam with the half of the walnut-sugar mix.
Repeat with the second piece of dough and second half of jam and walnut mix.
Roll out the third layer. Put on the top.
Cover the baking pan with a towel and allow to rise the dough for 1 1/2 hours, in room temperature.
Heat the oven to 350F (180C) and bake the cake for 25-30 min, until the top are light-browned.
Take the cake out from the oven, allow to cool for an hour.
For topping: melt the chocolate pieces, add oil and spread immediately