- Pre-heat oven to 180°C and lightly grease two baking trays.
- Add the butter and sugars to a large bowl and beat until creamy, light and fluffy.
- Add one egg, then beat until well incorporated. Add the second egg and vanilla extract and beat until they are also well incorporated.
- In a separate bowl, add the flour, cocoa powder, baking soda and the salt and mix until everything is combined.
- Slowly add the dry ingredients to the wet ingredients, scraping down the sides of the bowl as needed. The cookie dough will become very thick. You only need to mix until everything has combined.
- Add half the chocolate chunks to the cookie dough and stir until they are evenly distributed.
- Measure a rounded tablespoon of cookie dough and drop onto baking trays, making sure there is enough space for the cookies to spread. Press a few of the remaining chocolate chunks onto the top of each cookie.
- Bake for 9-12 minutes or until the cookies have puffed a little and the tops are dry. Cool on baking trays for at least 5 minutes before transferring to a cooling rack to cool completely.