Spray a 9-inch loaf pan with no stick baking spray and line pan with a strip of parchment paper the length of the pan. Spray the paper.
Sift the flour, baking powder, baking soda, salt together in a medium bowl and set aside.
In a separate bowl with an electric mixer beat the butter and cinnamon together and slowly add the sugar until light and fluffy; scrape down sides now and then. Incorporate the eggs one at a time, add one third of the flour, a third of the mascarpone, and third of the sour cream. Incorporate the rest in same fashion until just blended, do not over mix. Fold in the bananas and chocolate chips.
Pour batter into prepared pan and set in the center of the oven and bake for 1 hour and 15 mins. Remove from the oven, remove from pan and set on wire rack to cool completely. Serve warm or at room temp. Pound cake will keep in refrigerator for one week or 3 weeks in freezer wrapped airtight.