1 very ripe medium banana (the more ripe, the more sweet/less bitter it will be)
1 ripe baby avocado (or 1/2 regular size avocado)
sweetener of your choice - to taste
1 tablespoon ground flaxseed (optional)
1 scoop protein powder (optional)
ice - 4-6 cubes
I usually put cold rice milk in first (you can use any plain or vanilla beverage - I use organic rice milk, which is not vanilla but still slightly sweet) - up to almost the top of the blending metal things. The more beverage you add, the more liquidy your smoothie will be.
Then add chopped up banana and avocado. Blend until the smoothie is a nice, even green color. Add the flaxseed and protein powder - blend until the specks seem to be evenly distributed.
Now is the time to taste - if the smoothie is too liquidy, try adding another 1/2 or whole banana. If the smoothie is too bitter, add sweetener to your taste. If the smoothie is too warm (I always use cold rice milk, so I only sometimes have to add ice), add ice. Pulverized ice generally makes for a smoother smoothie - since my ice cubes rarely get completely churned.
Pour into a large mug or glass, and enjoy! This is my favorite breakfast smoothie.
Source of recipe: I wrote this recipe.