Stir mascarpone and maple syrup until smooth. Put in a cool place. Cut the papayas in half, peel and remove the seeds. Sprinkle the papaya halves with sugar and caramelise in the under the hot grill or in the oven for about 5 minutes until golden.
Take them out and let them cool down. Arrange the papayas on plates. Use a tablespoon to pierce the noodles from the mascarpone cream and arrange on the papayas. Coarsely crumble the walnuts, sprinkle over them and decorate with mint