Place the frozen banana slices into your blender, creating a base that will make the smoothie extra creamy and naturally sweet.
Add the peanut butter on top of the banana, which will give the smoothie its signature rich, nutty flavor and velvety texture.
Pour in the milk of your choice—dairy, almond, soy, or coconut—to help blend everything smoothly and to adjust the thickness.
Toss in the ice cubes, which will chill the smoothie and give it a refreshing, thick consistency.
If you like, sprinkle in a pinch of cinnamon or add a handful of spinach to introduce a subtle spice or a boost of greens, blending them into the mix.
Secure the lid and blend on high for about 30-45 seconds, or until the mixture is thick, smooth, and creamy, with no visible chunks.
Stop the blender and check the texture—if it’s too thick, add a splash more milk and blend briefly; if it’s too thin, toss in a few more ice cubes and blend again.
Pour the smoothie into glasses, and if desired, garnish with a light sprinkle of cinnamon or a drizzle of honey for extra flavor.
Enjoy immediately for the best creamy texture and fresh flavor, or chill for 10-15 minutes if you prefer it colder.