Banana and blueberry muffins

Every time I have a surplus of ripe bananas at home and I can't find a way of using them immediately I place them in the freezer - they last long there and can be used in most baking recipes after being thawed. However, when there is only one frozen banana to be used things get a bit more complicated, since most recipes call for 2-3 bananas, or even more (that was when I had to drop the idea of