- Step 1
Preheat the oven to 180C. Line a baking tray with baking paper.
- Step 2
Place the butter and brown sugar in a bowl and beat with electric beaters until thick and pale. Add the vanilla extract and egg, then continue to beat until just combined. Sift in the flour, baking powder and a pinch of salt and gently fold to combine. Stir through the chunks of dark and white chocolate.
- Step 3
Place tablespoonfuls of mixture on the tray, spaced 4-5cm apart. Bake for 15-20 minutes until golden.
- Step 4
Cool for 5 minutes on the tray, then transfer to a wire rack to cool completely.
- Step 5
Store cookies in an airtight container for 2-3 days.