1. Slice the Swiss roll thinly and pack on the bottom and up the sides of a 24cm silicone cake mould. Sprinkle 10ml (2t) sherry all over the cake.
2. Cut the Neapolitan ice cream into 2cm slices, with all three colours in one slice. Arrange a layer on top of the cake layer.
3. Scatter the fruit and half the jelly powder over.