Caramelised white chocolate and miso brownies

• 150g white chocolate (30% cocoa solids), chopped
• 250g unsalted butter, plus extra to grease
• 320g golden caster sugar
• 150g dark chocolate (at least 70% cocoa solids), chopped
• 170g plain flour
• 4 medium free-range eggs
• 2 tbsp white miso paste

1. Heat the oven to 120°C fan/gas 1. Put the white chocolate on a baking tray in a single layer and roast for 1–1½ hours, stirring the chocolate every 10 minutes with a silicone spatula (see Know How). The chocolate will go grainy at first but when it’s ready it should be smooth, spreadable and lightly golden.
2. When the white chocolate is almost ready, grease and line the tin with butter and baking paper. In a large heatproof bowl, melt the butter and sugar over a pan of barely simmering water. Put the dark chocolate in another heatproof bowl. Once the butter has melted, swap the bowls over and melt the dark chocolate.
3. Allow the butter mixture to cool a little. Stir in the flour, followed by the eggs and a pinch of salt. Tip half the mixture (about 500g) into the melted dark chocolate and stir to combine. Scrape the roasted white chocolate into the remaining butter mixture, add the miso and stir to combine.
4. Turn up the oven to 160°C/gas 4. Pour half the dark chocolate mixture into the lined tin, then pour in half the white chocolate mixture. Repeat until all the mixture is used up, then swirl with a skewer to create a marbled effect. Bake for 35-40 minutes until slightly flaky on top but still gooey in the middle. Leave in the tin to cool completely, then cut into 16 pieces and serve.