Add all of the ingredients to a blender and process 1-2 minutes, or until your smoothie is thick and creamy.
You can use all sweet potatoes or all bananas if you like. I personally love this smoothie with just sweet potato. If you're worried about tasting them, a little peanut butter completely masks the taste, but I don't really notice them, even with just the almond butter.
I like to soften my dates before adding them to my blender to help release their sugars and make them easier to process. Just add the chopped dates to a small bowl with about 1 tablespoon of water and microwave on high for 30 seconds.