Peel and slice the banana ahead of time if not already frozen, and store it in the freezer until ready to use (this helps create a thicker, creamier smoothie).
Add the frozen banana, Greek yogurt, protein powder, almond butter, almond milk, and ice cubes to a blender.
If desired, include optional ingredients like honey or maple syrup for sweetness, and chia seeds or flaxseeds for extra nutrition.
Blend on high speed for 30-60 seconds, or until the mixture is smooth and creamy. Stop and scrape down the sides of the blender if needed to ensure everything is fully incorporated.
Check the consistency. If the smoothie is too thick, add a splash more almond milk and blend again. If too thin, add a few more ice cubes or a bit more yogurt and blend.
Pour into a tall glass or portable bottle and serve immediately. Enjoy your protein-packed smoothie as a quick breakfast or post-workout refuel!