Soak cereals and raisins in milk for 5 minutes. Cream the shortening and sugar together and beat in the egg until smooth. Sift together the flour, baking powder and salt. Stir into the shortening mixture alternating with the cereal mixture, only just until blended, taking care not to overmix. Fill greased muffin cups 2/3rds full and bake at 400ยบ; for 25 to 30 minutes.