This nutty version of the classic bake has already got the Hollywood Handshake seal of approval and can be put together in no time at all. Liam has used bar shaped moulds here, but you could use any silicone shapes that you like.
Preheat oven to 200°C/180°C fan/400°F/Gas 6.
For the shortbread base. Blitz all the shortbread ingredients in a food processor until they just come together. Alternatively, mix the flour, cornflour and salt together in a bowl, then add the butter and sugar and rub with your fingertips until the mixture is just beginning to bind. Add the vanilla bean paste and lightly knead.
Tip the dough out onto the worksurface and knead lightly into a dough. Divide into 9 balls and press into the base of each mould.
Place the mould onto a baking tray and bake for 10-12 minutes, until the edges of each bar are just beginning to turn golden.
For the peanut butter caramel, put the cream and vanilla bean paste in a small pan and bring just to the boil. As soon as the mixture begins to boil, remove from the heat and set aside.
In a separate pan, heat the caster sugar and glucose over a medium heat. Do not be tempted to stir the mixture or it could crystalise. If needed, brush down the sides of the pan with a little water to dissolve any crystals that might form around the edge. Once the sugar has dissolved, turn the heat up high until the sugar has turned a golden brown. This is your caramel.
Tip the cream into the caramel, being careful as it may spit. Stir together before gradually adding the butter. Stir in the peanut butter.
Return to the heat and cook until it reaches 120°C/248°F on a sugar thermometer. If you do not have a sugar thermometer, you can check to see if it is at the correct stage by dropping ½ tsp of mixture into a bowl of cold water. Leave to cool for a moment, then pick up the ball and if it is pliable, sticky and can be moulded in your fingers, then it should be at the correct stage.
Pour the caramel into a shallow baking tray, fold through the dry roasted nuts and set aside to cool slightly, but do not allow to harden.
Once the peanut butter caramel has cooled, spread evenly over the shortbread bases, leaving them in the moulds.
For the topping, melt the milk chocolate in a bowl suspended over a pan of simmering water, then spread over the cooled caramel layer. Sprinkle over the remaining nuts. Allow to cool completely before turning out.
Melt the white chocolate, spoon into a piping bag and drizzle over each millionaire’s shortbread bar.