For the tahini shortbread
For the tahini caramel
Preheat the oven to 180°C, gas mark 4.
To make the shortbread, place the cake flour, cornflour, icing sugar and salt in a stand mixer fitted with a paddle attachment and mix well.
Add the butter and tahini and mix until a soft dough comes together.
Press into the bottom of a lined, 20x20cm square baking tin.
Prick the shortbread with a fork and bake in the pre-heated oven for 15-20 minutes or until golden.
To make the tahini caramel, combine the tahini paste, sugar and condensed milk in a saucepan. Stir until dissolved and simmer gently until the mixture is thick and comes away from the sides.
Pour over the shortbread and allow to set until firm.
Spread the melted chocolate thinly over the caramel, sprinkle with the toasted sesame seeds and allow to set.