Preheat oven to 350 degrees and grease a 9 x 5 loaf pan with softened margarine. Place cubed bread in a large bowl.
In a small bowl whisk together ½ cup soy milk and the arrowroot powder till no lumps remain. Add 1½ cups soy milk, maple syrup, vanilla, cinnamon and nutmeg and whisk to combine.
Pour over cubed bread and stir to coat every piece. Allow to sit for at least 15 minutes for liquid to soak into bread. Depending on what kind of bread you use and how stale it is, add more soy milk (¼ cup at a time) and allow more soaking time till every piece of bread is saturated and there’s a little bit of extra liquid. Mixture should look mushy and wet.
Fold in chocolate chips and bananas (using hands is the easiest for this), mashing up a little bit of the bananas.
Pour mixture into loaf pan, patting down to make an even top.
Bake 28-35 minutes till top is puffed, slightly browned and feels firm. Allow to cool slightly before slicing and serving. Also pudding can be scooped with an ice cream scoop when slightly cooled.