This dessert has several components to prepare, but none of them are difficult. It uses pineapple three ways: roasted, dehydrated and in the sorbet.
Palm sugar is made in many southeast Asian countries and is often called specific names according to the type of palm the sap is harvested from: look for names such as gula melaka in Malaysia, gula jawa in Indonesia, and nam taan peep in Thailand. You can substitute unrefined cane sugar.
You can often find peeled pineapple in the market, which saves a bit of time.
Make the sorbet syrup. Pour 300ml (1¼ cups) of water into a medium-size saucepan and add the sugar. Place the pan over a medium flame, bring to the boil and stir until the sugar dissolves. Turn off the flame and cool the syrup to room temperature, then refrigerate until cold.
Remove the skin and eyes from the large pineapple (or have the fruit vendor do it for you). Slice the pineapple into rounds about 8mm (⅜ in) thick. Choose the 10 nicest pieces and use a cookie cutter of the appropriate size to cut out the cores. Set these pieces aside.
Purée the remaining pineapple slices in a blender or food processor, then strain the juice through a fine sieve. Measure out 150ml (⅔ cup) of the juice.
Mix the pineapple juice with the coconut milk and 300ml (1¼ cups) of the chilled sorbet syrup. Stir in the rum and lime juice, then process the mixture in an ice-cream machine. Transfer the sorbet to an airtight container and freeze for several hours.
Make the dehydrated pineapple. Preheat the oven to 120° C (250° F). Remove the skin and eyes from the smaller pineapple, then use a serrated knife to slice it into rounds about 3mm (⅛ in) thick. Use a cookie cutter of an appropriate size to remove the core from each slice.
Blot the pineapple slices with paper towels then place them close together on a baking tray lined with a silicon mat. Sprinkle the slices lightly but evenly with granulated sugar then turn them over and sprinkle with more sugar. Put the tray in the oven and bake the slices until dry, turning them over as needed. They won’t get crisp – they’ll be slightly pliable. Remove the tray from the oven and leave the pineapple to cool before packing the pieces into an airtight container. Turn the oven temperature to 200° C (390° F).
Just before it's time to serve dessert, make the roast pineapple. Lay the slices of the larger pineapple on a baking tray lined with a silicon mat. Crumble palm sugar over the slices until they’re covered lightly but evenly. Bake until the pineapple is tender and the gula melaka is bubbling and thick, about 10-15 minutes. Cool to room temperature.
To serve, put a slice of roasted pineapple on a plate. Top with a scoop of the pina colada sorbet.
Slice the passion fruit in half and scoop out the juice and seeds. Spoon some of the passion fruit over the sorbet and add a sprinkling of toasted dried coconut. Top with a slice of dehydrated pineapple, garnish with mint leaves and serve immediately. The leftover dehydrated pineapple can be kept in an air-tight container for at least a week; if the pieces get moist, dry them in the oven again.