Combine the peanut butter and yogurt in a blender. Blend until smooth.*
Add the banana slices and blend just until smooth and no longer chunky.
Serve:
Pour into serving containers and refrigerate or serve immediately. If desired, top with roasted peanuts for crunch.
Notes
*Depending on the thickness of your peanut butter, you may need to add 1-3 teaspoons of water as you blend the yogurt and peanut butter. Add it a teaspoon at a time to avoid it becoming too runny.