Preheat oven to 300° F. In a medium bowl combine flour, salt and soda. Mix well and set aside.
In a large bowl blend sugars with an electric mixer at medium speed. Add butter and mix to form a grainy paste.
Scrape down sides of bowl and add egg and vanilla. Beat at medium speed until light and fluffy. Add flour mixture, rice cereal and chocolate chunks.
Blend at low speed just until blended. Drop by rounded Tbsp onto ungreased cookie sheet 2 inches apart. Bake for 22-24 minutes.
Immediately transfer cookies to a cool flat surface.Makes 3 Dozen Source: