Crush the digestive biscuits and mix with the melted butter. Then tightly line a small ramekin with the biscuit mixture and refrigerate for 15 to 20 minutes.
In a bowl, mix the mascarpone cheese, icing sugar and vanilla extract together. Remove the ramekin from the fridge and top the biscuit mixture with the mascarpone mixture and refrigerate for a further 30 minutes.
Before serving, top with the sweet popcorn and chocolate chips.