These were really good! I omitted the nuts and substituted about a tablespoon of applesauce for one of the tablespoons of butter. They were still wonderfully soft and moist! Next time I will try to sub more applesauce for more of the butter. I didn't measure how much banana I used - just used the 2 very ripe bananas I had on hand and that seemed just fine! These made very nice looking, full muffins and they were all gone in a matter of minutes. Next time I'll double the recipe!!