1. Add 9 cups of cereal in a large bowl and set aside.
2. In a microwave safe bowl combine butter, RX Nut Butter, and chocolate chips. Microwave 45 seconds then stir.
3. Microwave in additional 10-second increments until everything is melted and stirs together smoothly.
4. When the chocolate chips are almost melted, stir in vanilla.
5. Pour melted ingredients into the large bowl containing the cereal. Fold cereal into mix.
6. After everything is well coated, place into a one-gallon plastic bag and add about 3/4 cup of powdered sugar.
7. Close the bag and shake until evenly coated.
8. Place puppy chow on a parchment paper to cool.