In a large bowl, measure cereal and set aside.
Microwave chocolate chips, peanut butter, and butter uncovered for 1 minute. Stir.
Microwave about 30 seconds longer until mixture is smooth.
Stir in vanilla.
Pour mixture over the cereal and stir until evenly coated.
Pour into two gallon-sized resealable bags.
Add powdered sugar to one bag and crushed chocolate cookies into the other.
Seal the bags and shake until well coated.
Spread onto waxed paper to cool.
Mix together in a bowl and add gummy worms.