Line an 8 x 8-inch pan with parchment paper and set aside.
In a large mixing bowl, combine the oats, crispy rice cereal, cocoa powder, and protein powder.
In a microwave-safe bowl or in a small saucepan, combine the almond butter with maple syrup and heat until the mixture is melted.
Add the liquid mixture to the dry mixture, and add the peppermint extract and stir until combined. If the batter is too crumbly, slowly add water until it's thick and able to be shaped into mounds.
Transfer the mixture into the pan and press firmly with your hands. Top with chocolate chips. Refrigerate for about 30 minutes, or until firm.
Notes
Water: Depending on the protein powder you use, you'd likely need more water than just one tablespoon. Casein and brown rice are naturally thicker, so you'd likely need up to 1/2 cup of water (or more).
Leftovers: Keep in the fridge, covered, for up to 2 weeks. Freeze for up to 6 months.