Cream together the butter and sugars for a couple minutes with an electric mixer (or stand mixer) until well combined.

Scrape down the sides of the bowl, and add the egg and vanilla extract. Mix until just combined.

Now add the cocoa, flour, salt, and baking powder and mix until a dough ball begins to form. You may need to mix by hand a little as this dough is fairly dense. Then stir in the chocolate chips.

On a baking sheet lined with a baking mat or parchment paper, divide the dough into six balls. Bake at 350°F for 16-18 minutes. If you are aiming for slightly gooey centers, remove right at the 16 minute mark, but if you want them a bit more cooked through, then add on a minute or two. Again, these are inspired by Levain Bakery, which boasts very gooey centers, so I’m not going to tell you the right answer here but… I think you know it in your heart.

Remove to a cooling rack and allow to cool for a few minutes before enjoying.