Cut each banana into 6 chunks, and freeze until rock solid, preferably overnight.
With the acai inside the packet, crush the puree into smaller pieces. Process the pieces in a food processor to a fine slush. Add the frozen banana chunks, coconut oil and maple syrup, and begin to process (the food processor may jolt in the very beginning). As the bananas break down and combine with the acai, the mixture will look crumbly, then gooey and eventually smooth and slightly slushy, like a sorbet. Stop the food processor frequently to scrape down the side of the bowl and break up any clumps. Serve right away, or scrape into a container and freeze until ready to serve.
* Percent Daily Values are based on a 2,000 calorie diet. Your daily value may be higher or lower depending on your calorie needs.