Measure out 9 cups of Chex into a bowl (any kind will do - I like Rice best)
In a microwave-safe bowl, melt chocolate chips, peanut butter, and butter.
Stir until smooth (Microwave for 10 more seconds if needed)
Next, stir in 1 tsp of Vanilla and pour over the bowl of Chex cereal, mixing gently until completely incorporated.
Before it has a chance to cool - place into a big ziploc bag containing 1 1/2 Cups of Powdered sugar - seal and shake.