Divide Chex cereal into two large bowls (2 ½ cups in each) and set aside.

Place 1 cup powdered icing sugar in a gallon-sized ziptop bag and set aside.

Scrape Oreo filling out of cookies and set aside. Place Oreo cookies in a food processor and blend until fine crumbs remain.

Place Oreo crumbs in a gallon-sized bag and add ½ cup powdered sugar. Seal and shake to combine.

Place white chocolate chips in a small microwave-safe bowl and melt for 25 seconds. Stir and reheat as needed. Add Oreo filling and stir until completely combine.

Pour white chocolate mixture over one bowl of the Chex cereal and stir to coat.

Scoop the Chex cereal into the bag with the (plain) powdered icing sugar, then seal and shake to coat the cereal completely with the powdered icing sugar.

Place chocolate chips in a small microwave-safe bowl and melt for 25 seconds. Stir and reheat as needed.

Pour melted chocolate chips over the second bowl of Chex cereal and stir to coat.

Scoop the Chex cereal into the bag with the Oreo crumb and powdered icing sugar mixture, then seal and shake to coat the cereal completely.

Pour the two sugar-coated cereal mixtures onto a cookie sheet and allow the chocolate to set completely, approximately 30 minutes.

Stir the two cereal mixtures together before storing or serving.

Optionally, garnish with mini Oreo cookies.