Gently pour 9 cups of Chex cereal into a very spacious mixing bowl. Set it aside for now.
In a saucepan, melt the butter, semi-sweet chocolate chips, and creamy peanut butter together over medium heat. Stir constantly until the mixture is completely smooth and combined. Remove from the heat and stir in the vanilla extract. Let it cool slightly for 2-3 minutes.
Carefully pour the warm chocolate mixture over the Chex cereal in three stages, gently folding as you go. Be sure to toss very gently to coat all the cereal pieces evenly without crushing them.
Take a large, sealable plastic bag and combine the 2 cups of powdered sugar and 1 cup of festive sanding sugar inside. Give the bag a good shake to mix them thoroughly.
Add the chocolate-coated Chex cereal into the bag in batches. Seal the bag and shake gently until the cereal is fully covered with the sugary blend. Remove the coated cereal to a wax paper or parchment-lined baking sheet.
Spread the coated cereal in a single layer on the baking sheet. Chill it in the refrigerator for about an hour to set the delicious coating. Once set, it's ready to serve and enjoy!
Notes
Nutrition per serving: Calories: 416 kcal Total Carbs: 78g Net Carbs: 72g Fats: 11g Protein: 5g