This is a classic cocktail combined with a classic dessert. The roasted pineapple gives the roulade a sweet and tropical tang.
Heat the oven to 200°C/180°C fan/400°F/Gas 6. First, start the filling. Drain the pineapple, reserving the syrup. Chop the rings into 1cm pieces and spread out in a large roasting tin. Drizzle over 2 tablespoons of the reserved syrup and roast for 20–25 minutes, until golden and sticky. Remove from the oven and set aside to cool.
Place the remaining pineapple syrup in a small pan with 25g of the caster sugar and bring to the boil. Reduce the heat and simmer to a thick syrup. Remove from the heat and leave to cool.
For the meringue, whisk the egg whites until stiff, but not dry. Add the sugar 1 teaspoon at a time, until it is all incorporated and the mixture is stiff and glossy.
Fold in the vinegar and coconut, then spoon the meringue into the lined Swiss roll tin and level out. Tap the tin on the worktop to remove any air pockets.
Bake the meringue for 8–9 minutes, until the top is lightly golden brown. Reduce the temperature to 180°C/160°C fan/350°F/Gas 4 and bake for 10 minutes more, or until the meringue is firm.
Remove from the oven and turn out onto baking paper dusted with icing sugar. Peel the lining paper from the base and leave the meringue to cool for 10 minutes.
To complete the filling, pour the double cream into a medium bowl. Add the remaining 25g of sugar, along with the mascarpone, vanilla paste, coconut rum, grated coconut and coconut extract. Whisk to stiff peaks.
Spread three quarters of the coconut cream evenly over the meringue and scatter three quarters of the roasted pineapple on top.
Using a sharp knife, score a line 1cm in from the short edge, nearest you, then fold the scored end and roll up the roulade using the baking paper to help lift and roll. Wrap the roulade in baking paper and chill for about 30 minutes.
Unwrap the roulade and place on a serving plate. Spoon the remaining coconut cream down the centre of the top of the roulade and arrange the remaining pineapple on top. Drizzle with pineapple syrup, spray with gold spray, then dust with icing sugar. Serve with the remaining pineapple syrup on the side.