For children who suddenly decide that they hate bananas (I'm looking at you, 8YO), you can make the smoothie without banana, pour some off into a glass, and then add the banana to the rest. Because it really is much better with the banana. (No it isn't, says the 8YO.)
1 pint vanilla frozen yogurt
1 cup milk
1/4 cup natural peanut butter
2 tablespoons unsweetened cocoa powder
1 tablespoon honey (or sugar)
Mix everything together in a blender on high, and voila. Serves 2, maaaaaybe 3.
Source: Adapted from Jon Olinto and Anthony Ackil of b.good.