Lightly grease a 9inch round cake tin.
Break the biscuits into crumbs and pour into a small bowl. Add 1 tbsp peanut butter to bring it all together.
Pour into the cake tin and press down firmly. Place in the fridge for two hours.
In the meantime you can make the cream cheese filling.
In a food processor, combine the icing sugar, peanut butter and cream cheese together. Process until it is well combined. Give it a good mix with a wooden spoon scraping the mixture off the sides.
Remove the base from the fridge and pour the cream cheese on top. Place in the fridge to set for another hour.
Remove from fridge and take it out of the tin. The tin gives it the perfect round shape.
Using your hands, cover the outside of the cake with the nuts. Gently pat down firmly with your hands being careful not to squash it.