In a large bowl, combine the flour, cereal, baking powder, sugar and salt. In another bowl, beat the eggs, milk and oil. Stir into dry ingredients just until moistened. Fold in cream cheese and onions. Fill greased muffin cups two-thirds full. Bake at 400 degrees F for 15-20 minutes or until a toothpick comes out clean. Cool for 5 minutes before removing from pans to wire racks. Serve warm. Refrigerate leftovers.