Lay a large sheet of wax paper or baking parchment on the work surface and dust it evenly with 2 tablespoons of the sugar Place the egg yolfs in a heatproof bowl.
Add the remaining sugar and whisk with a hand-held electric mixer until the mixture thickens.
Sift in the cocoa, then fold in carefully and evenly with a metal spoon Whisk the egg whites in a clean, greasefree bowl until they form soft peaks.
Fold about 1 tablespoon of the whites into the chocolate mixture to lighten it, then fold in the rest evenly Scrape the mixture into the prepared pan, taking it right into the corners.
Smooth the surface with a metal spatula, then bake for 20-25 minutes or until firm and springy to the touch Turn the cooked cake out onto the sugar dusted wax paper and carefully peel off the lining paper.
Cover with a damp towel and let cool completely To make the filling: Whisk the cream with the whiskey or brandy in a bowl until the mixture just holds its shape, grate the coconut cream and stir in with the sugar Uncover the cake and spread about 3/4 of the cream mixture to the edges.
Roll up carefully from a long side.
Transfer to a plate, pipe or spoon the remaining cream mixture onto the top.
Use a vegetable peeler to make cocokut and chocolate curls to decorate the top of the cake.