Mix together the sugars and melted butter with a whisk until well combined and creamy. Add the egg and whisk until it is completely combined.
Place the flour into the mixture without sifting it. Mix it around gently but thoroughly, trying not to let in too much air.
Add in the chocolate chips then mix them in too. Once well combined spoon onto a baking tray making sure you keep them spread well apart, usually you can only fit 5 onto a normal baking tray.
Bake in the oven for approximately 10 to 15 minutes. They are cooked when the edges are just starting to crisp up and wrinkle, turning golden brown. If the middle still looks raw, tap the tray onto a surface. The cookies should collapse, this is what the self-raising flour does. Once they fall in on themselves, they crack. Once this happens all over the top of the cookie, they are done. Take them out the oven and transfer them to a plate or cooling rack. Once they have cooled a little they should be just the right, bendable and chewy.