1. Preheat the oven to 180C Fan. Line the base and sides of a 13in x 9in rectangle baking tin (I just use a baking tray).
2. Melt the chocolate in a bowl set over a pan of barely simmering water. (Do not let the base of the bowl touch the water.
3. Place the egg whites in a large bowl and whisk until stiff but not dry. If you turn the bowl upside down, the whites should be stiff enough not to fall out.
4. Put the egg yolks in a separate bowl with the sugar and whisk using the same whisk (no need to wash it!). Then add the raw cacao powder.
5. Pour in the cooled chocolate and gently fold together until well combined.
6. Gently stir two large spoonfuls of the egg whites into the chocolate mixture to loosen the mix, then fold in the remaining egg whites using a large metal spoon (you don’t want to squash out the air you have just beaten in).
7. Pour the mixture into the prepared tin and gently move the tin around until the mixture is level.
8. Bake in the preheated oven for about 20-25 minutes until risen and the top feels firm and slightly crisp.
9. Remove from the oven, leave in the tin (expect it to fall and crack a little) and set aside until cold.
10. Soak the oats in the water with the cinnamon and date syrup for 20 minutes. (I do this in a blender to save washing up).
11. Melt the raw cacao butter in a bain-marie on a low heat and add to the oat mixture and blend until a smooth consistency.
12. Turn the roulade out on to the paper so its lining paper is on top, then carefully peel off the paper. Spread the roulade with the whipped cream, leaving a border of about 2cm/¾ inches all the way around the edges.
13. Make a cut along one of the shortest edges facing you with a sharp knife, cutting about halfway through the sponge. This will help to start the rolling up.
14. Now roll this cut edge over tightly to start with and use the paper to help continue the tight rolling, by pulling it away from you as you roll. Don’t worry if the roulade cracks - that is quite normal and all part of its charm.
15. Finish with the join underneath then lift the roulade onto a serving plate or board using a large wide spatula or two fish slices. Dust with corn flour and decorate with pomegranates for a festive touch.