If using a food processor: Place the bananas in a food processor fitted with the S blade. Turn the machine on. The bananas will get knocked around and make a lot of noise. This is normal! Keep processing until the bananas start to develop a whipped, light, creamy texture; stop when they resemble frozen yogurt. This will take 4-5 minutes. Patience is key. If your bananas are still not getting whipped up by the processor after 4 minutes, add 1-2 tablespoons nondairy milk to get things moving. When the mixture is creamy, with a rich, whipped texture, add chocolate chips, coconut, or any other mix-ins you like. Pulse to combine. Serve immediately.