Banana Bread with Fresh Blueberries Recipe

"When I saw this recipe called for whole wheat flour for half the flour I thought I would give it a try. It turned out pretty good as far as taste but I had a hard time getting the center of the loaf done. I made one big loaf 9x5x3 loaf and when I took it out of the oven I thought it was done but once it cooling on the rack, the center caved in and I could see it was still doughy yet the bottom and sides were already browner than I would like. I am not sure how to get a loaf this size to be done in the center without the bottom and sides getting over baked. Next time I will put in small loaf pans or muffin tins. Maybe that will allow the bread to cook more evenly."