Preheat your oven to 325 degrees. Spray a baking sheet with nonstick spray.
In the bowl of a stand mixer, cream the butter and sugar until fluffy. This will take at least 2-3 minutes.
Blend in the eggs for about 30 seconds and add in the cocoa powder, salt, and baking powder. Blend until smooth (1-2 minutes). Scrape the sides and bottom to ensure everything gets in.
Using the dough attachment mix in the flour until incorporated. Don't overwork the dough! Fold in the chocolate chips.
Form about 12-15 dough balls (yes, these cookies are best big!). Use your hands to flatten each ball into a cookie shaped disc. You can leave them round for a very tall rounded cookie, but I think I've decided I like the flattened version better. Bake for 12-13 minutes.
Move from the baking sheet to a wire rack to cool. I found that I could do this immediately upon removal from oven, but if you have problems then wait a few minutes before continuing.
Serve warm with plenty of milk :) Microwave the leftovers, if any, for 10 seconds for that fresh-from-the-oven taste.