Preheat oven to 350 degrees. In a med bowl sift together the flour and baking soda. Using a mixer, beat butter on med-high speed until fluffy. Slowly add sugar and continue to beat until the sugar is blended with the butter. Add the eggs one at a time beating between each egg. Continue beating the butter mixture and slowly incorporate the banana beating well. Add the flour and baking soda to the butter and banana mixture and beat until well blended. Add girardelli brownie mix and mix by hand to incorporate the brownie mix without breaking the chocolate chips. Pour the batter into 2 prepared loaf pans. Bake for 1 hour at 350 degrees.