Preheat the oven to 350F then line a baking sheet with parchement paper and set aside.
Cream butter, brown sugar, and granulated sugar until light and creamy. Mix in the egg and the vanilla extract until combined.
½ cup butter, ¾ cup brown sugar, 2 tablespoon granulated sugar, 1 large egg, 2 teaspoon vanilla extract
Add the flour, cocoa powder, baking soda, and salt and mix until the flour mixture disappears. Fold in the chocolate chips. Scoop out 9 equally sized cookie dough balls with a large cookie scooper (about ¼ cup), and place those cookies on a baking sheet leaving about 2 inches of space between each one.
1 & ¼ cup flour, ½ cup dutch processed cocoa powder, ½ teaspoon baking soda, ¼ teaspoon salt
Gently press down on the cookies to about 1 inch in thickness, and bake in the preheated oven for 10 minutes. Once the cookies are baked, let them cool down on the baking sheet for 10 minutes before transferring them to a cooling rack.