Add dark chocolate chips to a small mixing bowl. Melt the butter (either in the microwave or on the stovetop), and pour it over the chocolate chips. Let stand for several minutes.
In another small mixing bowl, add flour, cocoa powder, baking powder, and salt. Whisk to combine. Set aside.
After 3-5 minutes, stir the chocolate and butter until combined and smooth. Set aside. (If there are still chocolate chips that didn't melt, heat the mixture in the microwave in 15 second intervals, stirring after each, until no chips are left.)
To the bowl of a stand mixer fitted with the paddle attachment (or large mixing bowl) add eggs, brown sugar and granulated sugar. Beat on medium low speed for about 2-3 minutes, or until mixture is thickened and turns a pale orangey tan color.
Add the melted chocolate and beat again until combined.
Add flour mixture you set aside earlier and beat until just combined.
Cover the mixing bowl tightly and refrigerate for at least 30 minutes.
While dough is chilling, preheat oven to 350°F and line a baking sheet with parchment paper. Set baking sheet aside.
Use a cookie scoop to form cookie dough balls approximately 1 inch in diameter. Place balls on prepared baking sheet, leaving about 2 inches of space between each ball. (If dough is too difficult to handle, it may need a little longer in the refrigerator.)
Bake for 8-10 minutes, until edges are set. Remove baking sheet from the oven and leave the cookies on the sheet for 5 minutes before removing from the pan and onto a wire rack to finish cooling.
Repeat steps 9 and 10 until all dough as been used.