Add Greek yogurt and milk to a high-powered blender.
Add peanut butter, protein powder, cinnamon, and vanilla.
Add frozen banana pieces.
Blend on low, gradually increasing the speed.
Stop and scrape down the sides as necessary.
Use a blender tamper if available.
Add additional milk only 1 tablespoon at a time if needed.
Blend until thick, creamy, and spoonable.
Taste and add optional honey or maple syrup if desired.
Scrape into a wide breakfast bowl.
Top with banana, berries, granola, and chia seeds.
Finish with a small drizzle of peanut butter.
Serve immediately.