Millionaire's Shortbread
For the Shortbread
200 g flour
150 g cold butter
75 g fine sugar
¼ tsp salt
For the caramel
200 g white granulated sugar
30 g unsalted butter, room temperature, cubed
120 ml whipping cream, warmed
½ tsp fine sea salt
For the chocolate
100g milk chocolate
100g pure chocolate
50g white chocolate
Preparation
Rub the cold butter into the flour with your (cold) hands until it resembles coarse breadcrumbs. Then mix in the sugar and salt. Bring it together only enough that it holds when squeezed—don't knead it into a smooth dough.
Press it gently but evenly into the tin, prick with a fork, then chill for 20–30 minutes before baking.
The key is keeping the butter cold and not overworking the dough. Warm/soft butter becomes more thoroughly incorporated into the flour and can give you a denser, less "short" texture. Cold butter + minimal handling gives you that delicate, crumbly, slightly sandy proper shortbread you're looking for.
Bake for 40+ minutes until dry and slightly golden color starts developing. Let cool fully before layering caramel.
For the caramel melt the sugar in a thick bottomed pan on medium heat. Let a deep amber color develop - this is what creates that deep caramel flavor. Once done, take off fire and slowly stir in the butter. Then warm the cream and stir it in too. Put it back on the medium fire and cook it again. Once ready add the salt and pour over the shortbread. Let cool fully.
Melt the milk and pure chocolate au bain marie, and pour it over the cooled caramel layer. Then melt the white chocolate and make zigzag stripes and cross them 3-4 times vertically with a knife to pattern score. Cool in the fridge overnight.