In the bowl of a stand mixer (with paddle attachment fixed), whip together the butter, oil and sugars until light and fluffy. Add each egg, one at a time, making sure the first one is fully incorporated before you add the second one. Add the vanilla extract and peanut butter and mix again until smooth.
In another bowl, whisk together the flour, cocoa powder, baking soda, baking powder and sea salt.
With your stand mixer set on low, slowly add the dry ingredients to the wet until they are just incorporated. Do not overmix. Gently fold in the chocolate chips, peanut butter chips and pretzel pieces.
Wrap the dough tightly in plastic wrap and place in the refrigerator to chill for 2-4 hours.
Preheat your oven to 350 degrees F and line 2 large baking sheets with parchment paper or silicone mats.
Scoop heaping tablespoons of the dough onto the prepared baking sheets. I baked approximately 8 per sheet.
Bake at 350 degrees F for 8-10 minutes or until the edges are set. The cookies will still be soft in the middle. Remove from heat and set aside to cool for 2 minutes on the pan and then transfer the cookies to a wired rack to cool the rest of the way.
Store in an airtight container for about a week. Enjoy!