>> source: allaboutyou.com / SHE magazine
>> servings: 8
>> time: 40 minutes plus chilling

Grease and line the base of a #20cm square loose-bottomed cake tin{} with baking parchment.

Place @shortbread biscuits{225%g} in a #food processor{} and blend until they form fine crumbs, then stir in @melted butter{25%g}. Press down into the tin to make an even layer. Chill for ~{60%minutes}.

For the filling, place @butter{175%g} and @soft brown sugar{150%g} in a #non-stick pan{} over a low heat, stirring until the butter melts and the sugar dissolves. Add @condensed milk{397%g} (1 can) and bring gently to the boil, stirring continuously, to make a golden caramel. Remove from the heat. Carefully spoon the caramel evenly over the biscuit base. Return to the fridge to chill for ~{60%minutes} to ~{120%minutes} or until set.

Melt @dark chocolate{125%g} and @white chocolate{125%g} in separate #bowls{} over pans of gently simmering water and stir @sunflower oil{1%tsp} into each. Pour the dark chocolate over the caramel, spreading it out to the edges. Repeat with the white chocolate, but swirl with a #fork{} to create a marbled pattern. Set aside. When the chocolate has hardened a little, cut into squares and serve.