1. Put the 1/2 banana in a microwave-safe bowl and zap it (in the microwave, of course) for about 30 sec. If the banana doesn't look kind of melted then zap it for about 30 sec. more.
2. Take it out of the microwave and stir it. Add the cocoa and sweetener.
3. Spread peanut butter on one slice of vegan bread and the banana mixture on the other. Press them together and enjoy! But, if you want some thing a little extra, then just toast it on both sides in a non-stick skillet. I think that this melts the flavors together nicely.