To a large microwaveable bowl, add the almond butter and heat for 15-20 seconds, or until almond butter is thin and easy to stir.
To the bowl, add the cocoa powder, milk and maple syrup. Stir until a smooth consistency is reached. There shouldn't be any lumps of cocoa powder. Taste test to see if you prefer more sweetener or salt. Serve immediately or seal and refrigerate for up to 1 week (the frosting may keep shorter or longer depending on your environment so this is ultimately up to your personal judgement).
Notes
*you can substitute cashew butter, peanut butter or sunflower butter with varied results in flavor