In a small bowl, mix together the peanut butter, maple syrup, and protein powder, to your desired sweetness. The caption said, "You want it to be thicker than caramel, but not dry like a dough," so it doesn't ooze out the sides while you're stacking the rice cakes.
Spread the protein-packed nut butter on one rice cake, add another rice cake, smear more nut butter, and add a third rice cake. Repeat so you have two bars.
For the coating, melt the chocolate in a separate small dish in the microwave until smooth. Dip the peanut butter rice cake bars into the melted chocolate, covering it completely. If you want less chocolate, you can just drizzle it on top. Optional: sprinkle the tops with a little sea salt. Place the two bars on a parchment-lined cookie sheet or plate. Freeze for 10 minutes and then enjoy the chocolate nutty crunchy goodness!