Stir together flour, soda and salt. In large bowl, beat margarine and sugar until light and fluffy. Add eggs and vanilla. Beat well. Mix in flour mixture. Stir in crushed cereal. Drizzle melted chocolate over the dough. With knife, swirl chocolate gently through dough to achieve a marbled appearance. Drop by rounded measuring-tablespoon** onto greased baking sheet. Bake at 350 degrees F, 12 minutes or until lightly browned. Remove from baking sheets. Cool on wire racks.