Preheat oven to 350°.
Place first 4 ingredients in a large bowl; beat with a mixer at medium speed until blended. Lightly spoon flour into dry measuring cups; level with a knife. Combine flour and remaining ingredients, stirring with a whisk. Stir flour mixture into banana mixture. Drop dough by 2 tablespoonfuls onto parchment paper-lined baking sheets. Bake at 350° for 19 minutes or until lightly browned. Remove from pan; cool completely on a wire rack.