Preheat the oven to 180oC and line a loaf tin with baking paper.
Cream the butter and sugars together until light and fluffy and add baking powder and salt and vanilla extract.
Add in the egg and mix with a wooden spoon. Add in flour and chopped chocolate. Mix all the ingredients together and then loose balls shapes, roughly the size of a golf ball.
Pop them on a lined baking tray with roughly 5cm space around them.
Bake them for around 8 minutes. Once out of the oven, cool on a wire rack (on top of baking paper) for at least 15 minutes before enjoying.
Notes
Makes 25 golf ball-sized balls which will become palm-sized cookies.
No need to refrigerate the cookie dough - size and pop onto a tray and into the oven!
If stored in an air-tight container they can last for about five days.