Great British Bake Off champ John Whaite has created an unbelievably moist and decadent cake that con only be described as ‘a show-stopper’.

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
• 200ml water
• 1 tsp bicarbonate of soda
• 1 tsp salt

For the salted caramel icing

• 250g light soft brown sugar
• 150ml double cream
• 140g butter, softened
• ½ tsp salt

For the ganache

• 250ml double cream
• 250g dark chocolate, finely chopped or grated
• Sea salt crystals

Method:

1. Heat oven to 160°C/140°C fan/gas 3. Grease and line a 25cm round deep cake tin with baking parchment. In a large bowl, mix the oil, egg yolks, vanilla paste, caster sugar and water until well combined. Sift in the cocoa powder and whisk until smooth.

2. Sift in the flour, bicarb and salt. In a separate bowl, whisk the egg whites to stiff peaks. Fold into the batter with a large metal spoon and mix until everything is well combined.

3. Gently pour the mixture into your cake tin, then bang it on the work surface twice to expel any large air pockets. Bake for 1 hr 10 mins or until the cake springs back when gently prodded and an inserted skewer comes out clean. Cover with foil after 1 hr if the cake starts to get too dark.

4. While the cake bakes make the salted caramel icing. Heat the brown sugar, salt and cream in a saucepan until the sugar has dissolved. Bubble for a few mins, then leave to cool. Beat the butter until smooth, pour in the cooled cream mixture and continue mixing until softly whipped. Chill until needed. When the cake is baked remove it from the oven, cool in the tin for 10 mins, then transfer to a large wire rack and peel off the parchment. Leave until completely cool.

5. To make the ganache, heat the cream until just boiling. Remove from the heat and pour over the chocolate. Leave to stand for a few mins until the chocolate has melted and you have a smooth sauce consistency.

6. To finish, slice in half and fill with the salted caramel buttercream. Spoon the chocolate ganache over the top and decorate with the sea salt crystals.