1. Preheat oven to 350 degrees F. Line two baking sheets with parchment paper or a silicone baking mat.
2. In a medium bowl whisk together the flour, cocoa powder, baking powder, baking soda and salt; set aside.
3. Beat together the butter, peanut butter and both sugars on medium speed until light and fluffy, about 3 minutes, scraping the bowl as needed. Add the eggs one at a time, beating well after each addition. Add the vanilla extract. Scrape the bowl. Add the dry ingredients and mix on low until just combined. Using a rubber spatula, stir in the chocolate chips and peanuts.
4. Drop by two heaping tablespoonfuls of dough, spacing the cookies about 2 inches apart. Sprinkle a small pinch of coarse salt on top of each cookie. Bake for about 12 minutes, or until the outside of the cookies are set but the middles are still a little soft. Cool cookies on the baking sheets. Store in an airtight container.