The egg and milk need to be at room temperature and the butter softened. Beat the butter, sugar and egg with a mixer, add the milk, then the honey and beat to a homogeneous mixture.
Pour the mixture into a container, with a nonstick coating if possible, and put it on the stove to boil. The mixture needs to boil on low heat for about 10 min. while stirring nonstop - in that time it needs to thicken and gain a light golden, caramel color.
The dough can be kneaded even when it's still warm. Roll out each ball into a thin round layer. Even if it's not perfect, you can finish shaping it after right it's baked.
Bake the layers in a preheated 356°F (180 °C) oven for 5-6 min. in a tray with baking paper.
After you take the layers out of the oven, cut them into a round shape using the cake form you intend to make the cake in or with a plate and a sharp knife.
That way your layers all end up the same size and once ready, the cake will be perfect. Cut and shape the layers while still warm because when they cool they harden and become crumbly - it's much harder to cut them at that point.
Roll out, bake and shape all of the layers the same way, then leave them to cool well.
To make the cream mixture for the cake, beat the sour cream and sugar with a mixer (optionally you can add 2 vanillas as well).
Repeat this order until out of layers and cream, be sure to finish off with cream. Sprinkle the cake generously with ground walnuts on top and leave it in the fridge for 3-4 hours for the layers to soak in the cream and jam well.
It's best to leave it for 24 hours. Before serving, release it carefully from the ring and sprinkle with walnuts again.