How to make
Crumble the biscuits to a sand-like consistency.
Crumble the cake to fine crumbs. You can use a store-bought cake or make your own by following the recipe for plain cake.
Put the crumbled biscuits and cake in a bowl, add the cocoa, cognac, jam and walnuts.
Melt the butter in a pour it in the bowl, pour in the milk and mash the cake mixture very well with your hands, so that all the ingredients mix together. You have to obtain a homogeneous, sticky, wet mixture. If you notice that the mixture is too dry, pour in a little more milk to moisten it.
Cover the bowl with foil and put it in the fridge for 30 min. to cool and for the butter to harden. This will make it easier for you to form the rocks.
Wet your hands a little before you form them, so the dough doesn't stick to them.
Once the mixture hardens, form rocks with your hands by taking a little from the mixture, forming it into a ball and then carefully pulling one end.
Try to make them approximately the same size. Arrange the prepared rocks upright in a plate, with a little space in between, and put them in the fridge again for 30 min. to harden.
Make a chocolate ganache by putting the confectionery cream on the stove. Before it comes to a boil, remove it from the stove, put the crumbled chocolate in it, leave it for a few seconds and then stir until it melts and you get a homogeneous chocolate mixture.
Take the rocks out and pour chocolate ganache with a spoon over each one.
Put them back in the fridge to cool.
