In the canister of a blender, add the oats, milk, yogurt, cocoa powder, honey/maple syrup, and vanilla.
Blend until smooth and no chunks remain.
Pour into two mason jars or an airtight container(s) with lid.
Refrigerate for at least 4 hours, or preferably overnight, so that the oats will soften and absorb the liquid.
When ready to serve, remove from refrigerator, crumble a mini chocolate muffin on top (if desired), and enjoy.
