To prepare a spiced chocolate chip banana cookie bars recipe, first preheat the oven to 350?F (180?C) and grease and flour two 9-inch square pans. Set aside. Sift the flour, baking powder, cinnamon, nutmeg and salt into the bowl of an electric mixer and beat on medium speed until the mixture is light and fluffy, about 2 minutes. Add the chocolate chips and mix until they are evenly coated. Pour the batter into prepared pan and bake in the preheated oven for 20 to 25 minutes, or until toothpick inserted in center comes out clean. Let cool in pan for 5 minutes before transferring to wire rack to cool completely.