1. Place water, maple syrup and cocoa powder into a food processor or blender and process.
2. Add the peanut butter or coconut oil, and process again until smooth. Voilà!
I find that peanut butter is wonderful in this recipe, but the coconut adds a depth to the chocolate flavor. I find that if I am making a strictly chocolate cake/muffin/brownie recipe, the coconut flavor works best, but otherwise I say go with the peanut butter!
If you reduce the ratio of cocoa powder, you get a liquid consistency; this can be great on a single layer cake or brownies since the frosting will flow to the edges and make a shiny, smooth surface. Then, just stick it in the fridge and thanks to the peanut butter or coconut butter, it solidifies, so you have an excellent smooth surface with no sacrifice to the flavor (seriously awesome with brownies).
Source of recipe: This recipe was modified from this one at http://thedailyrawcafe.com [1].