Preheat oven to 350 (325 for glass dish). In a 13x9 baking pan, melt margarine/butter in the oven.

Sprinkle crumbs evenly over the margarine/butter; pour sweetened condensed milk evenly over the crumbs.

Top with chips; press down firmly.

Bake for 25 to 30 minutes or until lightly browned.

Cool.

Garnish as desired. Cut into bars. Store loosely covered at room temperature.