Chocolate Mousse

Ingredients

• 4 large eggs, separated
• 200ml double cream
• 50g caster sugar
• 1/4 tsp fine salt
• 25g unsalted butter
• 220g dark chocolate (70%), chopped
• 1 tsp vanilla extract
• 1 tsp espresso powder (optional)
• 100ml double cream (for caramel)
• 150g caster sugar (for caramel)
• 1/2 tsp sea salt flakes
• 50g unsalted butter (for caramel)
• 100g fresh raspberries to serve (optional)

Method

1. Melt the chopped dark chocolate with the 25g butter in a heatproof bowl set over a pan of barely simmering water, stirring gently for 4-5 minutes until silky and glossy. Lift off the heat and stir through the espresso powder and vanilla. Leave to cool for 5 minutes so it thickens slightly but still pours from the spoon.
2. Whisk the egg yolks with half the caster sugar (25g) for 2-3 minutes until pale and ribbon-like — the trail of the whisk should sit on the surface for a couple of seconds. Fold into the cooled chocolate until glossy and smooth.
3. Whip the double cream to soft, floppy peaks — stop before it stiffens. Fold a third into the chocolate to loosen, then fold in the rest with a light hand to keep the mousse airy.
4. In a clean bowl, whisk the egg whites with the salt to soft peaks, then add the remaining 25g sugar and whisk to stiff, glossy peaks that hold their shape on the whisk. Fold a spoonful into the chocolate to slacken it, then fold in the rest in two additions until no white streaks remain — billowy, not dense.
5. Divide between six ramekins or glasses, smooth the tops, and chill for at least 2 hours, ideally 4, until set with a slight wobble in the centre.
6. For the caramel, melt the 150g sugar in a heavy-based pan over a medium heat without stirring, swirling occasionally, for 6-8 minutes until a deep amber. Whisk in the butter — it will hiss and bubble — then pull off the heat and slowly stream in the warm cream, whisking until glossy and smooth. Stir in the sea salt flakes and let cool for 5 minutes until pourable but not runny.
7. To serve, spoon a generous puddle of warm caramel over each mousse so it pools and slides down the sides, scatter with raspberries and a final pinch of sea salt flakes.