1. Preheat the oven to 180°C (350°F). Line a baking sheet with baking parchment and set aside. Chop the chocolate and melt about 9 oz. (250g) of the chocolate in the microwave or in a heatproof bowl over a pot with simmering water. Let it cool down again. Chop the pecans and set aside.

2. Add the butter and sugars to a large bowl and mix until light and fluffy. Add the eggs one after another and mix well after each addition. Next, add the vanilla extract and mix it in. Add the melted chocolate and mix it in. Add the flour, cocoa powder, baking powder and salt to a separate bowl, mix and then add to the bowl with the other ingredients and mix until just combined – do not overmix. Finally, add the remaining chopped chocolate, chopped pecans and crushed cornflakes and fold them in.

3. Use a spoon or cookie scoop* and place dough balls with enough space in between on the baking sheet and bake them for about 15 minutes – the edges should be crisp and the surface should have some cracks. Take out of the oven and let cool down on the baking sheet for some time, then transfer to a wire rack and let cool down completely. Repeat with the remaining dough.