Stuffed Christmas tree

Prepare the cake following the < a href = "http://www.cucinare.meglio.it/ricetta-pan_di_spagna_-_ricetta_base.html" > basic recipe of the sponge and allow it to cool.

Melt the chocolate in a double boiler, mix in ricotta and 600 g 50 g of chopped pistachios.

Divide the cake into three parts according to the height obtained, practicing two longitudinal cuts, and moisten the parts obtained with the liquor.

Distribute one-third of the filling prepared on the first layer of sponge cake proceeds; overlap the middle layer and sprinkle with another third of the compound.

Mix the ricotta with the cocoa and a teaspoon of butter.

Overlap the last part of the sponge to closure and spread the mixture, making sure to coat the edges well.

The mixture distributed externally, practicing the lines with the tines of a fork to distribute the remaining pistachios, part of which crumbled, and refrigerate.

If liked, sprinkle the surface of the cake with icing sugar before serving.