Rub the flour and butter together, then stir in the icing sugar.
Mix in the beaten eggs and vanilla seeds, wrap in cling film, and chill for one hour.
Roll out the pastry, line a 20cm tart ring, and blind bake at 180°C for 15-20 minutes.
Slice bananas lengthways and cook sugar and butter in a non-stick pan until caramelized.
Coat the bananas in the caramel and cream, then pour the mixture into the tart case.
Rub together the crumble flour, caster sugar, and cinnamon to sprinkle over the tart.
Bake the tart for ten minutes until the topping is golden.
Heat the cream in a pan, then remove from heat and add the chocolate.
Stir the mixture until the chocolate has completely melted into a sauce.
Slice the tart and serve drizzled with the warm chocolate sauce.