Method
1. Pre-heat oven - 180°C / 355°F
2. Add dark chocolate and butter to a clean medium bowl
3. Heat in double boiler until completely melted and let cool - low heat
4. Add caster sugar, cornflour, baking powder, egg and vanilla extract to a clean stand mixer bowl
5. Beat until light and fluffy
6. Fold mixture melted chocolate to the batter
7. Fold chocolate chips and sultanas into the batter
8. Let cool in fridge
9. Prepare a clean baking sheet with parchment paper
10. Spoon batter into baking sheet one by one
11. Bake and let cool - 12 min, 180°C / 355°F