Add nut/seed butter and chocolate to a bowl and microwave 30 sec at a time and stir until all chocolate is melted and smoothly combined.
Pour this over the cereal and stir to cover all the cereal pieces, refrigerate 5 min to cool the mixture to room temperature.
Sprinkle 2 tbsp powder sugar and stir to coat. Refrigerate again 5-10 minutes until the pieces are no longer wet looking. Sprinkle the remaining powder sugar to coat completely.