3/4 c. light corn syrup
1 (11.5 oz.) pkg. milk chocolate chips
1 tsp. vanilla
3 tbsp. butter
9 c. Golden Grahams cereal (12 oz. box)
3 c. miniature marshmallows

Grease rectangular pan, 9x13x2 inches. Heat corn syrup, butter, and chocolate chips to boiling in 3-quart saucepan, stirring constantly. Remove from heat; stir in vanilla. Pour over cereal in a large bowl; toss until completely coated with chocolate. Fold in marshmallows, 1 cup at a time. Press mixture evenly in pan with buttered back of spoon. Let stand until firm, at least 1 hour. Cut into squares. Store loosely covered at room temperature, no longer than 2 days.