whisk the egg whites on a stand mixer and slowly add in the caster sugar.

Whisk to form a meringue that is firm but still creamy - at this point, add in the egg yolks.

Sieve the cocoa powder and flour together and fold through the meringue

Spread out onto a 60-40 cm tray lined with grease proof paper
Bake in the oven at 170°c until the sponge bounces back when pressed lightly
As soon as it comes out of the oven remove from the tray and place face down on to grease proof paper
The sponge can now be frozen until needed

Place the egg white and the sugar into a machine bowl
Place the bowl into warm water and heat the mix to 40c whilst whisking
Place onto a stand mixer and whisk untill cold

Add in the soften butter

Fold in the melted W2 white chocolate

Temper the W2 white chocolate

Add in the grape seed oil and emulsify

Add in the black cookie pieces

Spread a 1 cm layer of butter cream on to the sponge and then roll up
Freeze
Place the roll on to a cooling rack
Glaze the roll, if you would also like the base covered once the top layer has set dip the bottom into the glaze to give an all round coverage.