Spray pan and rubber spatula or wooden spoon with vegetable pan spray. In large saucepan, melt margarine; add marshmallows. Cook and stir until melted. Add cereal and mix well. Spread into prepared pan.
When cool to touch, cut into bars. Melt candy according to package directions. Dip bars into melted candy; tap gently to remove excess candy and place on parchment paper. Drizzle with additional melted candy, sprinkle with jimmies or add icing decoration, as desired.