In a double boiler, melt the butter and chocolate until no clumps of chocolate remain.
Meanwhile sift the flour, cocoa powder, baking soda and salt in a medium bowl. In a large bowl mix the eggs, sugar and vanilla until thoroughly combined. When melted, pour the chocolate and butter slowly into the egg mixture while stirring. Be careful not to add the chocolate too fast, or the eggs could cook. Mix well.
Add the sifted dry ingredients, and mix until completely incorporated. Scrape the sides and bottom of the bowl to insure that any butter or flour pockets are incorporated.
Add the peanut butter chips and mix until evenly distributed in the dough. Be sure to scrape the bottom of the bowl so every cookie gets some goodies!
Scoop the dough onto a baking sheet lined with parchment or wax paper.
Chill the scooped cookies in the freezer or refrigerator for 30 minutes.
Bake at 325 degrees for about 16 minutes. The cookies will appear cracked with large fissures across the tops when finished.