Add the powdered sugar to a gallon-sized sealable bag.
Put the peanut butter and chocolate chips into a microwave-safe bowl and heat in 20-30 second increments, stirring between each one. Do this until the chocolate is fully melted and smooth.
Stir the peanut butter mixture into the popcorn gently. Coat entirely.
Add a few cups of the coated popcorn into the sealed bag and shake.
Pour the coated popcorn into a large bowl and continue the process with the rest.