Method

• 1.
  Preheat the oven to 190°C.
• 2.
  In a food processor, whiz the butter with the caster sugar and brown sugar until creamy. Add the beaten eggs and vanilla extract and whiz again.
• 3.
  Fold in the sifted flour, baking powder and 1/2 teaspoon of salt until a stiff batter forms.
• 4.
  Stir the finely chopped chocolate into the mixture, reserving 1 tablespoon for topping.
• 5.
  Drop heaped tablespoonfuls of mixture onto non-stick or baking paper-lined baking trays, allowing about 2cm between each for spreading. Scatter a little of the reserved chocolate on top. Bake the cookies for 9-10 minutes until lightly golden, but not browned, then remove from the oven. Leave on the trays for 5 minutes to firm before transferring to a wire rack to cool. When the cookies are cool, store in an airtight container.