-chocolate chips Preheat the oven to 350 degrees. Butter a 9x13-inch baking pan. In a large bowl, sift together the flour, baking powder, baking soda and salt. In another bowl, using a handheld electric mixer, cream together the butter and sugar until combined. Beat in the bananas until combined. Beat in the eggs and vanilla, beating well. Beat the flour mixture into the butter mixture until combined. Stir in the sour cream or yogurt. Stir in the chocolate chips. Scrape the batter into the prepared pan. Bake for 45 to 50 minutes, or until a toothpick inserted in the center comes out clean. Transfer the cake to a wire rack and cool completely. ----