Line the base of a 20cm spring-form tin with a disc of baking parchment
Mix the butter and crushed biscuits. Press the crumbs into the bottom of the tin. Chill in the refrigerator for 30 minutes, then top with ½ the caramel and return to the fridge
Arrange ½ the sliced banana pieces around the edge of the prepared tin. Beat together the cream cheese and sugar in a mixing bowl
Fold the yoghurt into the cream cheese mixture
Spoon the filling into the tin, keeping the banana around the edge. Spread level with the back of a spoon, cover and chill overnight until firm. Place the cheesecake in the freezer for 30 minutes before unmoulding to firm up
Carefully remove the cheesecake from the tin and put on a serving plate topped with the remaining banana peeled and sliced, and drizzle with the remaining caramel
Grate over the chocolate and serve!