Add all ingredients to a blender and blend until smooth.
If the smoothie isn't cold enough, blend with a few ice cubes (not too many or you’ll dilute the flavor).
Drizzle 1 tsp unsweetened peanut butter (melted) on top and serve.
Spinach-Free: Although the baby spinach is virtually undetectable in the smoothie, you can omit it if desired.
Protein Powder-Free: If you don't want to add protein powder to your smoothie, add 1/2 tsp vanilla extract and keto-friendly sweetener to taste (if you use a sweetener like erythritol or Swerve, 2 tbsp is a good starting point). If the result is too thin, add a pinch more xanthan gum.