Grease a 22cm round pie tin and line the base with baking paper.
Using a food processor, pulse biscuits 2-3min., until they are the texture of fine breadcrumbs.
Add cocoa powder, pulse further 1min. You will now have chocolate crumbs.
Place crumb mixture into a medium sized mixing bowl with melted butter. Stir until well combined. Spread crumb, butter mixture evenly across base of prepared tin. Using the back of a metal spoon, press down on the surface so that the base is tightly packed. Place in the refrigerator, prepare filling.
Place cream into a small saucepan and gently heat. While warming, break confectionary into pieces, place into the cream, and stir until confectionary has melted evenly throughout. Stir in vanilla.
Pour mixture onto the prepared base. Allow to cool to room temperature, cover with cling film and refrigerate 4hrs (or overnight).
Cream and cocoa powder provide the protein in this tart.