Whip the cream with the powdered sugar and the first of the rose water and vanilin until you get stiff peaks. Spoon into a container and leave in the fridge.
Sieve together the cake flour, baking powder and salt.
Mix together the eggs, the second lots of rose water and vanilin, then sieve in the sugar. Next, beat until quadrupled in volume, then little by little beat in the flour till fully combined.
Spoon the mixture out into a prepared, lined, baking tray, then spread out with a spatula, then bake for 12 minutes at 360°F
Remove from the oven, trim the crusty edges, then flip onto a new piece of baking paper and peel off the old piece. Cut a diagonal line down one of the long ends of the cake, then roll up and leave to cool entirely.
Finally, once the cake is cool, unroll, then spread over the cream mixture from earlier, and roll back up. Either leave to set in the fridge, or enjoy right away!