Mix the yogurt, cocoa and sweetener

Crush the biscuits into small chunks and fine bits

Use some spray oil to coat the inside edges of the rings

Spoon the biscuit crumble into 2 bottomless ring moulds or egg rings

Gently layer the chocolate yogurt on top and press down gently (you do have to be delicate here)

Put the whole thing (plate, ring moulds etc) into the freezer for 30mins

Bring the cheesecakes out of the freezer and use a knife to loosen the edges of the moulds and add berries... hey presto!