Preheat oven to 375°F and line baking sheet with parchment paper.
Combine cocoa, flour, baking soda, and salt and whisk to combine. In a second bowl combine corn syrup, egg white, and vanilla.
Beat butter and sugars together in stand mixer or with hand mixer until the color has lightened and mixture is light. Add in liquid mixture and mix on med-low until fully incorporated. Add in flour mixture at a low speed until just mixed in. Stir in pretzels, choc chips and peanut butter chips by hand.
Cover bowl and chill dough for 30 min.
Scoop dough into about 2 tbsp portions. Cook for 10-12 min, edge of cookie will most likely be more set than center. Keep cookies on baking sheet for 5 minutes after removing from oven before transferring to cooling rack.
Notes
Chocolate cookie recipe adapted from America's Test Kitchen's Chewy Chocolate cookies.