Cut away the skin from the pineapple and cut the flesh into thin slices. Chop the pineapple into small pieces, discarding the central core. Put in a bowl and stir in the raisins, 2 tablespoons of the honey and 2 tablespoons of the rum.
Grease a baking sheet. Roll out the pastry on a lightly floured surface to a 28 cm (11 inch) square. Trim off the edges and cut into 5 even-sized strips. Cut across in the opposite direction to make 25 squares. Using the tip of a sharp knife, make a shallow cut, 1 cm (½ inch) away from the edges, to make a rim. Beat the egg yolk with the remaining honey and brush over the pastry rims.
Bake in a preheated oven, 220°C (425°F), Gas Mark 7, for 15 minutes, or until risen and golden. Scoop out the centres of the pastries to shape cases and return to the oven for 5 minutes. Transfer to a wire rack to cool. Beat the mascarpone with the icing sugar and remaining rum and spoon into the cases. Pile the pineapple mixture on top to serve.