First prepare the cream. Heat the whipped cream and melt the cooking chocolate in it. Stir in the coconut blossom sugar and hazelnuts. Allow to cool and place in the refrigerator.
In the meantime, separate the eggs for the sponge cake roulade. Beat egg whites with a little lemon juice until stiff. Mix egg yolks and powdered sugar until foamy. Add the coconut liqueur.
Preheat the oven to 180 °C. Cover a baking tray with baking paper.
Mix the flours and add to the yolk mixture alternately with the beaten egg whites. Spread the dough on the prepared tray and bake for about 15 minutes.
Roll the roulade in a tea towel, peeling off the baking paper. Allow to cool. Roll up the roulade, remove the tea towel, spread the cream and roll up again.