Banana Muffins

I baked them for quite a while longer, and yet they never seemed to be done; I'm pretty sure the reason is that I had loads of mashed bananas - our bananas were quite large. Why did they ask for 'four bananas, mashed' in this recipe, but '200 g bananas, mashed' in the banana cake recipe just two pages later?

Also, I baked them early in the morning to have them ready for breakfast, which was definitely a mistake - I used normal flour and forgot to add baking powder, so the first few muffins came out really flat...