Preheat oven to 350 degrees F (175 degrees C). Grease a 12-cup muffin tin or line cups with paper liners.
Sift rice flour, sugar, almond flour, and cornstarch together in a large bowl.
Whisk 1/4 cup water and egg replacer in a bowl until smooth. Stir in remaining 1/2 cup water, mashed bananas, and vegetable oil. Add rice flour mixture, cinnamon, salt, and baking soda; mix until completely blended. Fold in chocolate chips.
Spoon batter into the prepared muffin cups, filling each 3/4 full.
Bake in the preheated oven until tops spring back when lightly pressed, about 30 minutes. Let cool slightly before serving.