Banana-Chocolate Marble Bread

This is such delight!  It's super moist and the flavors are absolutely amazing!  Enjoy!
-1/2 cup semisweet chocolate chips
-1/4 cup (1/2 stick) unsalted butter, at room temperature
-1 cup sugar
-2 large eggs
-3 very ripe bananas
-1/3 cup sour cream
-1 tsp vanilla extract
-1/2 tsp salt
-1/2 tsp cinnamon
-3/4 tsp baking soda
-2 cups flour
Preheat oven to 350 F.  Coat the sides and bottom of 9x5 loaf pan with baking spray (the one with flour and butter).  Set aside.
Melt the chocolate chips and set aside to cool.
In your mixer's bowl, cream the softened butter with the sugar and eggs.  Add the bananas and mix well.  Stir in the remaining ingredients. Once well combined, mix 1 cup of the batter with the cooled melted chocolate. 
Pour banana batter into prepared pan.  Top with the chocolate batter.  Using a knife, swirl batters a little.  
Bake in preheated oven for 60-75 minutes or until toothpick comes out clean.  Place pan on wire rack and cool for 10 minutes.  Remove bread from pan straight onto the wire rack and cool completely.  Slice and enjoy!