Melt shortening and butter over very low heat. Remove from heat; stir in sugar. Add egg and vanilla; beat well. Sift together flour, soda, baking powder, and salt; stir into sugar mixture. Blend in the rolled oats, corn flakes, and peanuts. Shape dough into 1-inch balls. Place 2 inches apart on greased baking sheets. Bake at 350° for 12 to 15 minutes.