To a mason jar or container with a tight-fitting lid, mix the oats, protein powder, coconut milk, and honey. Stir with a spoon to combine. (Just ensure there's enough room at the top of your jar or bowl to allow for expansion and prevent overflow)
Cover securely with a lid or plastic wrap and set in the refrigerator overnight (or for at least 6 hours) to set/soak.
Before serving stir in the peaches, top with yogurt, orange zest, and pistachio.