Billionaires Shortbread

Preheat the oven to 180°C/gas 4. Grease & line a rectangular tin (20x30cm) with baking parchment making sure some overlaps the edge of the tin. This will make it easier to lift out of the tin at the end.

Place the butter, peanuts, flour, corn flour & sugar into a food processor and blitz until it starts to clump together. Tip onto the work surface and knead until a dough forms then press this, evenly, into the prepared tin. Bake in the oven for 25 minutes until golden brown. Remove from the oven and set aside to cool.

Next place the butter and peanut butter in a saucepan and melt together over a low heat stirring until smooth. Sieve the icing sugar into a bowl then pour on the melted butter mixture and mix together. Then pour over the cooled base and spread out until even. Place in the fridge to chill for about 2 hours to set.

For the caramel layer pour the tinned dulche de leche or caramel into a saucepan with the salt and bring to the boil, then simmer vigorously for 2-3 minutes whisking all the time until it thickens slightly and the colour goes a bit darker. To test the caramel is ready put a teaspoonful onto a cold plate & put it in the fridge for 5 minutes, when chilled the caramel should be softly set, not runny. If it’s runny boil for a little longer. Leave to cool for 20-25 minutes then pour onto the peanut butter layer and put back in the fridge for another 2 hours.

Next melt the chocolate in a heatproof bowl over simmering water. Meanwhile melt the toffees and milk together in a saucepan over a low heat, they will eventually melt together into a runny toffee sauce.

Remove the tin from the fridge and pour the melted chocolate evenly over the top, then using a spoon drizzle the toffee sauce over the top of the chocolate in a loopy pattern or stripes if you prefer. Work quickly so the caramel doesn't set. Sprinkle over the flaked sea salt then place back in the fridge for a further 2 hours to set before slicing and serving.