Method

1. Preheat the oven to 180°C or (160°C fan-forced). Line two large baking trays with baking paper.
2. Use an electric mixer to beat the butter, sugar and vanilla until pale and creamy. Add the eggs one at a time, beating well after each addition. Sift together the flour and baking powder, add to the butter mixture and use a wooden spoon or spatula to mix until well combined. Mix in the chocolate.
3. Roll tablespoonfuls of the mixture into balls and place on the oven trays, leaving about 5cm between each for spreading. Flatten each ball to about 5 cm in diameter.
4. Bake in the preheated oven for 20 minutes, swapping the trays around halfway through baking, or until light golden and cooked through. Leave the cookies on the trays until cool (about 30 minutes).