How to make
Prepare a butter cream from 2 tablespoons of milk, 1 tablespoon rum, 2 tablespoons cocoa and 3 tablespoons sugar, which are heated in a pot on the stove until you get a homogeneous mixture. Leave it to cool and beat the butter with 1 cup of powdered sugar and add the egg yolks one by one.
Beat 2 egg whites with a pinch of salt into snow and add them along with the cocoa mixture. To prepare the cream, whip the sour cream with the remaining powdered sugar and vanilla and add the 2 egg whites, beaten into snow.
Arrange 2 rows of cats' tongues in an elongated tray, and 1 row along the side of the walls of the tray. Each biscuit is dipped for a second in milk. Pour in the butter cream and arrange 2 more rows of cat tongues, ending with the cream on top.
Optionally, decorate the cake with grated white or brown chocolate.
