Prep the banana: Peel and break into chunks. If using frozen banana, let it sit 2–3 minutes to soften slightly for easier blending.
Add base ingredients: In a blender, add milk, yogurt, banana, and peanut butter.
Boost gently: Sprinkle in ground flax or chia and cinnamon if using.
Keep add-ins simple for toddlers.
Blend until smooth: Start low, then increase speed for 20–30 seconds. Scrape down sides and blend again if needed.
Adjust texture: Add a splash of milk or water if it’s too thick, or a couple of ice cubes for a milkshake-like sip.
Serve right away: Pour into a small open cup or straw cup. Offer in small portions and refill as needed.