Melt margarine in a large saucepan over a low heat. Add marshmallows; stir until completely melted. Remove saucepan from heat. Using a buttered spatula or wax paper, press mixture evenly into 13 x 9 x 2-inch pan coated with cooking spray. When cool, cut treats into 2-inch squares.
Makes approximately 24 squares.
NOTE: Different variations can be made with Coco Krispies and Rice Krispies.Makes 4 Source: