Cream butter, sugars and egg in a large bowl until smooth.
In a separate bowl, mix together the flour, oats, cereal, baking powder and baking soda. Add to creamed mixture, mixing until thoroughly blended. Stir in chocolate chips. Drop dough by spoonfuls onto a greased baking sheet. Bake for 7 to 10 minutes, or until light golden.
Tip: For a softer cookie, allow the dough to chill in the refrigerator for 10 to 15 minutes before baking.