Mash the bananas with a fork, add soy yogurt and mix well.
In another bowl, mix oats and cinnamon and then mix them into the wet ingredients.
At the end, add any fruit or chocolate, mix slightly and pour into a baking tray lined with baking paper.
Bake for 30 minutes at 180°C, then let the pastry cool a little before slicing.
Store in a closed container in the refrigerator.