1. Heat oven to 375.
2. In large bowl, combine brown sugar, peanut butter, margarine and shortening; beat until light and fluffy.
3. Add egg; blend well.
4. Lightly spoon flour into measuring cup; level off.
5. Add flour, baking soda, baking powder and salt; mix well.
6. Stir in cereal. (dough may be sticky).
7. With lightly floured hands, shape level tablespoons of dough into 1 1/2 inch balls; roll in sugar.
8. Place 2 inches apart on ungreased cookie sheets.
9. With fork, flatten in crisscross pattern.
10. Bake at 375 for 7 to 10 minutes or until golden brown.
11. Cool 1 minute; remove from cookie sheets.