Reduce biscuits to crumbs via preferred method. I used my mini chopper because it's quick and easy. Pour into a bowl.

Melt butter in bain-Marie or microwave. Pour into the biscuits and mix with hands until all the biscuit crumbs are wet.

Press the biscuit mixture into the bottom of a 12 inch springform tin and put in the fridge to set. Make sure the layer is flat and even.

While the base sets, spoon the peanut butter into a small pan and put over a low heat. Stir in the milk until combined. Should be like soft playdough. Remove from heat.

In a separate bowl, mix together the cream cheese and sugar until smooth. Then add the peanut butter and mix until combined. Set aside.

Melt the chocolate in a bain-Marie or microwave (on super low heat). Slowly stir in the double cream. Consistency should be thick, similar to the peanut butter mixture. Remove from heat.

Take the base from the fridge. Spoon some of the peanut butter mixture into the tin and spread it across the whole base, covering it. Add uneven dollops of chocolate mixture. Repeat layering until all the fillings are in the tin.

Take a pallet knife, knife, fork or spoon handle (anything, really), push it into the mixture (not so far you touch the base) and swirl it about, to create a marbled effect. Be careful not to mix it into one colour.

Leave in the fridge to set. Preferably over night, but 6+ hours should be enough.

If desired, while serving a slice, sprinkle over some smashed peanut pieces.