Combine white chocolate chips and 2 Tbsp. shortening. Melt over low heat, stirring until smooth.
Add 1/4 tsp. cinnamon, 1/4 tsp. nutmeg, 1/4 tsp. rum extract, and 1/4 tsp. peppermint extract.
Pour white chocolate mixture over 6 c. Chex cereal. (I use a large paper grocery bag, but you can also do this in a very large mixing bowl.)
Stir or shake until cereal is coated in white chocolate.
Sprinkle powdered sugar and additional 1/4 tsp. cinnamon and 1/4 tsp. nutmeg over cereal mixture.
Shake or stir gently until cereal is coated in powdered sugar.
Sprinkle with Andes Peppermint Pieces.