The recipe involves melting and cooling butter, which I do in the microwave. Usually I remember to take it out and add it to the batter.
It wasn't till later, cake baked and cooling that I noticed the flashing signal telling me to retrieve the dish of butter.
Interestingly, it seems to me that there's no difference from the times I've remembered the butter. I'm guessing because there was a ton of apple. It's still one of the better banana breads I've made. I gave it ten extra minutes in the oven because of the apple. What's the function of the butter, then? I ask the expert bakers who read here.
I'll get Handsome Son's verdict later.