Method

1. Bring a pan of water to the boil, add the potatoes, and cook for 10-12 minutes until tender. Drain and run under cold water until cool enough to handle. Pull off any loose bits of skin and then finely grate the potatoes.
2. Line a 20cm square baking tin. Preheat the oven to fan 160ºC/180ºC/gas mark 6.
3. In a large pan, gently melt the butter, peanut butter and chocolate, stirring regularly to combine and stop the chocolate catching on the bottom.  Remove from the heat.
4. Use an electric whisk to beat the sugar and eggs for a few minutes until they are thick. Fold in the chocolate mixture until well combined, then gradually fold in the grated potatoes. Sift over the flour and cocoa and fold into the mix. Spoon into the baking tray and scatter over the peanuts. Bake for 20 minutes until just cooked but still a little wobbly. Cool in the pan for 10 minutes before transferring to a wire rack. Cut into squares and serve with the Jersey Salted caramel.