This is the quickest, most chocolaty dessert that you can whip up in literally 10 min. before guests arrive.
Melt 1 1/2 chocolate bars in a water bath, save the rest for decoration once you've made the cake.
Once the chocolate is ready, take it off the water bath and add the confectionery cream to it slowly right in the same container, while slowly beating with a mixer.
The goal is to obtain a fluffy chocolate mousse; its thickness and consistency depends on the amount of cream used. You can add pieces of chocolate if you like. Your cream is now ready.
For the biscuit layer, mash the biscuits finely, melt the butter and mix the 2 ingredients so that the biscuits take in the butter. Then pour them into a suitable container and mash with the oval part of the spoon so it's not crumbly.
Return to the freezer for about 5 min. to harden.
All that's left for you to do is to pour the ready mousse over the now-hardened layer, grate the rest of the chocolate on for decoration (and/or use whipped cream).
You can serve immediately or return to the freezer again for 1-2 hours.