Banana Chocolate Chip Cake with Sour Cream Chocolate Frosting

My spouse made this for our son's graduation party and it was so popular he has made it again, and wants to be sure we have it handy when he wants to make it next. It is from Simply Julia, which is a cookbook revolving around making things that taste good but do not reuire tons of time to accomplish. For me, that is what amounts to week night cooking. He doubles this, cooks it in two 11 x 15 pans, and makes it a party sized cake. The cake: 1 cup (125 g) flour 1 cup (125 g) whole wheat flour 1 cup (200 g) sugar 2 tsp. baking powder 1 tsp. baking soda 1 tsp. kosher salt 4 very ripe bananas 2 large eggs 1 cup (227 g) sour cream 1/2 cup (120 g) canola oil 6 oz. (170 g) chocolate chips (~1 cup) The Frosting: 6 oz. (170 g) chocolate chips (~1 cup) 1 cup (227 g) sour cream 1 Tbsp. maple syrup Preheat the oven to 350 degrees and prepare two 8" round pans. Combine dry ingredients and stir together, Smash the bananas in a separate bowl, and add wet ingredients and stir. Fold the dry ingredients into the wet ingredients and then add the chocolate chips. Divide batter into the 2 pans, and bake until the center is firm, about 35 minutes. Cool cakes and make the frosting by microwaving the chocolate chips until melted. It will probably take a minute, but do in 30 second bursts--stir after each because the chips retain their shape but can be melted inside. Add the sour cream and maple syrup. This is a very wet frosting so refrigerate before using. Frost the cakes the way you usually would and serve!