75g/2½oz caster sugar
50g/1¾oz cocoa powder, sieved
25g/1oz cornflour
2 tsp extra-virgin olive oil
½ tsp smoked sea salt flakes (see tip section)
¾ tsp smoked sea salt flakes
1 tsp vanilla paste or extract
2 x 154g/5½oz packets chocolate cookies, such as Oreos or Bourbons(28 small biscuits in all)
50g/1¾oz dark chocolate (min. 70% cocoa solids)
100g/3½oz dark chocolate (minimum 70% cocoa solids)
50g/1¾oz unsalted butter, softened
500ml/18fl oz double cream
4 tbsp full-fat milk
2 tsp instant espresso powder or strong instant coffee powder