Method

1. Preheat the oven to 190C/180C Fan/Gas 5. Grease a 32x23cm/13x9in tin and line with parchment.

2. For the caramel, put the sugar in a saucepan and melt over medium heat until dark brown in colour. Remove from the heat and carefully add the salt and half the cream. (CAUTION: boiling sugar is extremely hot. Handle very carefully.)

3. Once the mixture has settled, add the remaining cream and butter. If the mixture is lumpy warm it over a low heat and stir until smooth. Pour into a jug to cool.

4. For the brownies, sift the flour, cocoa powder and salt into a large bowl and set aside.

5. Melt the chocolate and butter in a pan over medium heat, remove from the heat and allow to cool slightly.

6. Whisk the eggs, sugar and vanilla extract in a large bowl until thick and pale. Whisk in the chocolate, then fold in the flour mixture until just combined.

7. Pour half the batter into the tin and smooth the surface using a spatula. Add a thin layer of the caramel, making sure to leave the edges clean. Add the remaining batter and gently level the top. Bake for 25-30 minutes, or until a skewer inserted in the middle comes out with just a few moist crumbs. Allow to cool completely in the tin.

8. Meanwhile, melt the white chocolate in a heatproof bowl set over a pan of simmering water (do not allow the bowl to touch the water). Leave to cool slightly then use a fork to drizzle it over the brownies. Leave the chocolate to set slightly before removing from the tin and cutting into 12 brownies.