Preheat oven to 180°C (355ºF). Place the butter, vanilla, sugar, egg, milk, flour, cocoa and baking powder in a food processor and process until a soft dough forms. Place dough in a bowl and stir through the chocolate chunks. Shape 2 tablespoons of dough into flat rounds and place, allowing room to spread, on baking trays lined with non-stick baking paper. Bake for 12–15 minutes or until brown. Cool on trays. Makes 18.
* To check if the cookies are done, look at the bottom not the top. If you wait until the top looks right you risk overcooking them. To check, lift a cookie with a spatula so you can see underneath. The bottom should be a deep brown colour. Cool on trays as the cookies will continue to cook after you’ve removed them from the oven.