Melt your chocolate chips in a microwave safe bowl. Stirring at 20 second intervals until smooth.
Pour over the dry chex mix and gently stir in until all the chex cereal is covered with chocolate.
In another bowl combine the brownie mix and powdered sugar, pour over the chocolate covered chex and stir around gently until all covered.
Transfer the cereal to another bowl, and dispose of any excess brownie mix. (I lifted it by the spoonful with a big slotted spoon) Fold in peanuts and caramel bits.