Line a large baking sheet pan with parchment paper. Peel and slice bananas into about 1/2 inch thick circles. Measure out 2 cups of sliced bananas which is about 3 bananas depending on how big they are. Layer each banana slice on prepped sheet pan making sure there's room between them and they're not touching. Freeze for at least 2 hours or preferably overnight.
Place frozen banana slices in a food processor. Add the rest of ingredients for which ever banana nice cream flavor you are making. Blend for about 2 minutes until smooth and creamy texture is reached. For some of the flavors like chocolate and mint chocolate chip, some of the ingredients may get stuck on the side of the food processor. Open it and scrape the sides and continue to blend for another few seconds making sure all the ingredients are well blended into the banana. Use a spoon and give the banana nice cream a gentle stir making sure there aren't any chunks left and that everything is well blended and smooth.
Depending on the temperature of your house and how long you have to blend the bananas to get it smooth and creamy, the bananas may start to thaw out a bit. If your nice cream seems to be too soft, place it on a freezer friendly container and freeze for 10-15 minutes.
Serve banana nice cream in a cone or bowl with your favorite toppings. Place any leftover banana nice cream in a freezer friendly container and keep frozen for 1-2 months. Allow frozen banana nice cream to thaw out on kitchen counter for 15 minutes to soften and be able to scoop out and serve. Enjoy!