Preheat oven to 350º F. Line an 8x8 pan with parchment, and set aside.
Into a medium sized mixing bowl, mix together the cacao powder, coconut sugar, arrowroot, sea salt, and baking powder. Stir to combine.
Into another medium sized bowl, mix together the eggs, SunButter, coconut oil (or avocado oil) maple syrup, and vanilla. Stir well.
Add the dry brownie ingredients into the bowl with the wet ingredients, and stir into a thick and sticky brownie batter.
Add the brownie batter to the prepared pan. It will be sticky, so it helps to use wet hands to spread the batter out in an even layer.
Top the brownie batter with the cookie dough. Sprinkle the cookie dough with chocolate candy pieces.
Bake the Monster Cookie Brownies for 16-18 minutes. Allow to fully cool (best if refrigerated at least 2 hours) prior to slicing.