Preheat the oven to 350 degrees F (175 degrees C).
Blend bananas, sugar, buttery spread, applesauce, and vanilla extract together in a food processor for at least 3 minutes. Add rice flour, baking soda, salt, and cinnamon and process until smooth. Scrape down sides and bottom as needed. Pour batter into mini muffin tins.
Bake in the preheated oven until muffin tops spring back when lightly pressed, about 9 minutes. Transfer to wire racks to cool.