Rice Cereal Treats

2 Cups miniature marshmallows
3 Cups crisp rice cereal
2 Tablespoons margarine
Vegetable cooking spray
Melt margarine in a large saucepan over low heat. Add marshmallows and stir until completely melted. Remove from heat. Add rice cereal and stir until well coated. Spray 8X8X2 inch pan. Using waxed paper or press mixture into pan. Cut into squares.