The Perfect Banana Tart Tatin

Name: Banana Tarte Tatin
Prep time: 20 min
Cook time: 1 h
Total time: 1 h 20 min
Yield: 1
Ingredients: 120g caster sugar; 110g butter, cut into cubes; 25ml dark rum; Pinch cinnamon; 4-5 bananas; pinch of sea salt; 500g pack ready-rolled all-butter puff pastry