Line a plate, small baking sheet, or tray with parchment paper and set aside.
Add the almond flour, chocolate protein powder, and cocoa powder to a medium mixing bowl. Stir until evenly combined.
Add the nut butter, maple syrup or honey, and vanilla extract.
Mix until the ingredients begin to form a thick chocolate dough.
Add milk 1 tablespoon at a time, mixing after each addition. Stop adding milk when the dough is soft and moist but still firm enough to roll.
Divide the mixture and roll it between your palms to make 8–10 evenly sized balls.
Arrange the Healthy Cosmic Brownie Protein Balls on the prepared plate or tray.
Place the chocolate chips and coconut oil in a small microwave-safe bowl. Microwave for 20–30 seconds at a time, stirring between intervals, until completely melted and smooth.
Dip each protein ball into the melted chocolate, allowing excess chocolate to drip back into the bowl.
Return the coated balls to the parchment-lined tray and immediately decorate with rainbow sprinkles, if desired.
Freeze for 20–30 minutes, or until the chocolate coating has set.
Enjoy chilled or allow the protein balls to soften slightly at room temperature before serving.