1. Place the Rice Krispie Treats into a Ziplock bag and add a few drops of orange food gel that has been mixed with a drop or two of water. Mix until the cereal has an orange tint.
2. Spray a microwave-safe bowl with non-stick cooking spray and heat butter and marshmallows on high for 30 seconds at a time until melted. Stir after every 30 seconds or so until completely melted.
3. Add a few drops of orange food gel into the melted marshmallows.
4. Add the Rice Krispies cereal to the marshmallows and stir until well coated.
5. Press the mixture into 8 x 6 x 2-inch pan coated with cooking spray.
6. Dump the cereal treat onto a piece of wax paper and cut out the pumpkin shapes and decorate them.