1. Make the dough

    Lightly grease and line a 20cm square tin with nonstick baking paper. For the shortbread, use an electric hand whisk to beat 125g unsalted butter and 60g golden caster sugar in a bowl until combined. Add 125g plain flour, 60g rice flour and a pinch of salt and beat again, until it starts to form a dough.

  2. Bake the shortbread

    Tip the dough into the tin. Press it down evenly with the back of a metal spoon. Prick all over with a fork and chill in the fridge for 1 hour to firm up. After 30 minutes, preheat the oven to gas 4, 180°C, fan 160°C. Once firm, bake for 25-30 minutes, or until golden and baked through. Leave to cool completely.

  3. Make the caramel

    To make the caramel, heat 200g caster sugar in a pan set over a medium-high heat. Keeping a close eye on it, let it melt without stirring, swirling the pan around often, so that the sugar melts evenly and doesn’t crystallize. Once a rich caramel colour, remove from the heat and carefully add 125g cubed unsalted butter, 100g light muscovado sugar and 175ml double cream.

  4. Layer it up

    Return to a low heat, and wait for any solidified sugar to melt. Increase the heat slightly and simmer for about 7 minutes, until smooth, thick and golden. Leave to cool for 20 minutes. Pour the caramel onto the shortbread and chill until firm, about 2 hours.

  5. Make the topping

    Break 200g white chocolate into pieces and melt in a heatproof bowl over a pan of simmering water. Divide between 4 bowls. Colour one with a few drops of pink gel food colour, one with blue, one with yellow and one with green. Break 200g of 70% cocoa solids dark chocolate into pieces and melt. Cool slightly then pour over the caramel.

  6. Decorate the topping

    Dot teaspoons of the 4 coloured white chocolates over the surface of the dark chocolate. Use a skewer to gently swirl the colours through the dark chocolate in a continuous motion without lifting the skewer. Top with white chocolate stars. Chill for 5 hours to firm up completely.

  7. Slice and serve

    Using a sharp knife, cut into 16 squares and serve.

    RFO HERO 636x418 Millionnaire mini

    Calories 397 (20%), sugar 29.8g (33%), fat 25.9g (37%), saturates 15.5g (78%), salt 0.028g (0%), based on 16 servings.

  8. Ingredients

    We've made a handy shopping list so you can get everything you need to make this indulgent billionaire's shortbread. Don't forget to screenshot before you go shopping!

    250g unsalted butter
    60g golden caster sugar
    125g plain flour
    60g rice flour
    200g caster sugar
    100g light muscovado sugar
    175ml double cream
    200g white chocolate
    200g 70% dark chocolate
    white chocolate stars, to decorate