In a bowl mix together the Greek yogurt, protein powder, and a splash of almond milk to thin the consistency.
In another bowl, mix the espresso with about ⅓ cup water. (If you're using strongly brewed coffee, do not mix with water.)
Submerge each rice cake in the espresso mixture, flipping to soak both sides very briefly.
Place the first rice cake in a small bowl. Top with half of the yogurt mixture. Follow with the other rice cake, then another layer of the yogurt mixture.
Refrigerate for 20 minutes if desired, then dust the top with cocoa powder and enjoy!