Cream butter with brown sugar and granulated sugar until light and fluffy.
Add eggs and vanilla and mix in.
Melt 1/2 cup chocolate chips and stir to incorporate.
In a separate bowl, whisk flour, cocoa powder, baking soda, and salt together. Add into wet mixture and stir until just combined.
Stir in 1/2 cup chocolate chips.
Chill dough for at least 10 minutes (up to 36 hours).
Preheat oven to 350 degrees Fahrenheit. Remove dough from the refrigerator and roll into balls, about one inch in diameter. Using a medium sized melon baller works great for scooping the dough. Tip: let thaw a few minutes if dough is very cold.
Place dough balls on a baking sheet lined with parchment paper, leaving about 1.5 inches between balls.
Bake 11-13 minutes, until set.
Let cool on the pan for about 2 minutes then transfer to a wire rack to cool completely. Enjoy!
24 servings
1 cookie