Turn the oven on to heat up to 356°F (180 °C). Lay out 2 forms with removable sides with baking paper. You can also bake the layers 1 by 1 in a single form.
Set aside 1/2 of both types of cream, use the rest for the mixture. Mix 1/2 the creams with the layer and stir until homogeneous. Then, mix with the rest of the flour.
Distribute the mixture into the forms or bake them separately in the same form. Bake them for about 30 min. Before you remove the baking paper, let them cool for 10 min.
For the mixture, beat the remaining liquid cream, then add the remaining sour cream and essence while stirring. Stick the baked cake layers together with this mixture, smear the rest of it on top of the cake.
Decorate with crumbled biscuits if desired and leave the cake for a few hours before serving.