Mix together cashew butter, maple syrup, milk, and vanilla extract until smooth. Add in pea protein and combine until no clumps remain.
Separate the batter in two bowls (about 3/4 cup for each). Mix 2-3 tbsp chocolate chips into one batter. For the other batter, mix in cacao powder and then add in the remaining 2-3 tbsp chocolate chips.
Portion out 16 (about 2 tsp) balls for each batter. Then, gently roll together one cookie dough and one brownie batter to form the brookie balls. Continue until all are combined.
* Keep protein balls in an airtight container in the refrigerator.