John Whaite's Chocolate chiffon cake with salted caramel butter cream - Good Food Middle East

Ingredients

• 125ml sunflower oil, plus extra for greasing
• 7 large eggs, separated
• 2 tsp vanilla bean paste
• 375g golden caster sugar
• 50g cocoa powder
• 300g plain flour
• 1 tsp bicarbonate of soda
• 250g light soft brown sugar
• 150ml double cream
• 140g butter, softened
• ½ tsp salt
• 250ml double cream
• 250g dark chocolate, finely chopped or grated
• sea salt crystals, to decorate