Combine the biscuit crumbs and butter then press into the base of a greased and lined 20cm round spring form pan and chill
Beat the cream cheese and sugar with an electric mixer until smooth. Add the gelatine, rum and chocolate and mix until smooth then fold through the cream
Pour the mixture over the prepared base. Chill for 3 hours or until set
For the salted caramel popcorn. Add the caster sugar and water to a small pan and stir over a low heat.
Once the sugar dissolves, turn up the heat to medium-high and allow the mixture to come to the boil, reduce the heat and allow the mixture to boil uncovered for around 8 minutes or until the mixture becomes lightly golden.
Note, that it’s really important that you don’t stir the mixture during this time and regularly brush the sides of the pan with water
Remove the caramel mixture from the heat, add the brown sugar and stir with a wooden spoon until combined.
Add in the cream and stir until combined.
Return to the stovetop and stir over medium heat for about 3 minutes, remove from heat and add salt to taste.
Pour mixture over popcorn and use a greased spoon to mix.
Gently pile popcorn mixture onto the chilled cheesecake