Prep your banana. If not already frozen, peel, slice, and freeze for at least 2 hours. Frozen banana makes the smoothie thick and creamy.
Add liquids first. Pour the milk into the blender.
This helps the blades catch and blend smoothly.
Add the rest of the ingredients. Drop in the frozen banana, peanut butter, cocoa powder, sweetener (if using), vanilla, and a pinch of salt. Add protein powder, oats, or seeds if you like.
Blend until smooth. Start low, then increase to high for 30–45 seconds. If it’s too thick, add a splash more milk.
If it’s too thin, add a few ice cubes or a bit more frozen banana.
Taste and adjust. Add a touch more cocoa for deeper chocolate, another teaspoon of sweetener if you prefer it sweeter, or a bit of salt to sharpen the flavors.
Serve immediately. Pour into a chilled glass and garnish with a sprinkle of cocoa, a drizzle of peanut butter, or a few cacao nibs for crunch.