1To make the espresso chocolate sauce, place the sugar in a medium pan over medium heat. Without stirring, allow the sugar to melt, brushing down the side of the pan with a wet pastry brush. Continue until the sugar reaches an amber colour. Carefully add the water, coffee beans, cocoa powder, salt and chocolate and bring to a boil. Remove from the heat. Pass through a sieve, then transfer to an airtight jar or container.
2Place the cold espresso, milk, ice cream, ice and 2 tablespoons of the espresso chocolate sauce in a blender and blend until combined.
3Drizzle the inside of a tall serving glass with espresso chocolate sauce. Pour in the mocha frappe, top with whipped cream and dust with cocoa to serve.
Tip: Store the espresso chocolate sauce in an airtight container in the fridge for up to 2 months. It's also great over ice cream.