Mix the sponge cakes with the butter. Spread the mixture in the prepared tin and press down firmly.
Mix all the ingredients together well and spoon onto the base.
Bake for approx. 30 mins. in the bottom half of an oven preheated to 220°C. Remove and let cool slightly. Remove the cake from the tin and place on a rack to cool. Cover and refrigerate for approx. 2 hrs.
Bring the sugar and all the ingredients up to and including the star anise to a boil and simmer approx. 10 mins. Remove the vanilla bean and star anise. Puree 1 tbsp of this sauce with the papaya. Add the lime sections to the remaining sauce and let stand for approx. 30 mins.