Melt the butter over medium low heat in a small sauce pan. Let cool to room temperature.
Meanwhile, sift or mix together flour, cocoa powder, salt, baking soda and baking powder in a medium bowl.
In a small measuring cup, add the eggs and vanilla extract, whisk together. Set aside.
Add the cool butter and sugar in another mixing bowl and beat with a paddle attachment on medium speed until fluffy and lighten in color, about 2 minutes.
Add the egg mixture to the butter/sugar mixture and beat on low speed to combine for 1 – 2 minutes.
Gradually add the flour mixture, scraping the side and bottom of the bowl as necessary.
Once all the flour is incorporated, turn the mixer speed to stir and add the peanut butter chips, mix until the chips are evenly distributed.
Refrigerate for at least 1 hour.
Preheat oven to 350°F.
Use a large ice cream scoop (the one I used is about 2 oz) to portion the cookie dough onto a parchment paper lined baking sheet 1” apart. Bake for 15 minutes. Bake in 2 to 3 batches.
Let cool on the baking sheet for 5 minutes then transfer with a spatula to cool completely on a wire rack.