Combine first 5 ingredients in a food processor; process until smooth.
Lightly spoon flour into dry measuring cups; level with a knife. Combine flour and next 5 ingredients (through salt) in a large bowl. Add banana mixture to flour mixture, stirring just until moist. Stir in chocolate chips and walnuts until well combined. Divide mixture evenly between 2 (9 x 5-inch) loaf pans coated with cooking spray.
Bake at 350° for 50 minutes or until a wooden pick inserted in center comes out clean. Cool in pans on a wire rack 10 minutes. Remove from pan; cool completely.
This is my go to banana bread or muffin recipe. I've been using it at least every other month since it was published. It's freezes beautifully and people never guess that it's whole wheat or healthy. I use King Arthur White Whole Wheat flour instead of the pasry flour.
I love finding recipes that use whole wheat flour and this one is great. I enjoy eating whole wheat baked goods, but I think the taste is so great you could pass this by even the most skeptical eater. I also love that it doesn't use eggs.
I thought I'd give this a 3, since it wasn't necessarily bad (and one star looks so sad!), but the reality is that I wouldn't bother making this again. I followed the recipe exactly. While it did have a nice flavor, it lacked the cakey moistness I seek in a good banana bread.