Start beating Marie biscuits until fine crumbs. Set it aside.
Mix up with coffee and hot water together and let it cool. Once cooled, mix it together with the cookie crumbs and stir together until well combined.
In a separate bowl, combine the whipping cream, mascarpone, sugar and the vanilla essence using a mixer at a high speed.
Press down the biscuit crumbs into a cup, then pour the mascarpone on top of the crumbs. Finish it up by dusting with some cocoa powder on top.