Grease and line the sides of a springform 20cm deep tin. Melt the butter in the microwave in short bursts and set aside.
Whizz the biscuits in a food processor until fine. Add the butter and whizz until well incorporated and the mixture resembles wet sand. Tip this into the prepared springform tin and press down firmly and evenly. Chill this in the fridge while you get on with the filling.
For the filling, put the two chocolates in a microwave-safe bowl and microwave in short bursts until fully melted. Stir well and set aside to cool slightly.
Using an electric whisk/free standing mixer, mix the mars capone, icing sugar and horlivka powder until combined. Pour in the melted chocolate and whisk again. Pour in the double cream and whisk until it starts to thicken to a firm mousse-like texture. Keep a close eye on this as it will thicken quickly and if you over-whip the double cream could split!
Gently fold in the chopped wispa bites and then dollop this mixture on top of the biscuit base. Smooth over, cover and chill in the fridge for at least 3 hours or overnight.
To decorate: first remove the cheesecake from the tin and place on your serving dish or plate. Spread the malteaser spread on top (You'll probably want to use about half a tub). Pop the remaining whole wispa bites and malteasers on top and enjoy!
