Pour Rice Chex cereal into a large mixing bowl. Set aside.

In a microwave-safe bowl, combine the semi-sweet chocolate chips, peanut butter, and salted butter. Microwave in 30-second intervals, stirring between each interval until the mixture is smooth and well combined. Be careful not to overheat. Then stir in the vanilla extract.

Pour the melted chocolate mixture over the Rice Chex cereal. Gently fold and stir until all the cereal is evenly coated. Take care not to crush the cereal.

In a large Ziploc bag or a paper bag, add the powdered sugar. Transfer the chocolate-coated cereal into the bag. Seal the bag and shake it vigorously to coat the cereal with powdered sugar evenly.

Spread the coated Muddy Buddies on a parchment-lined tray or a clean surface to cool. Allow them to sit for a while until the chocolate hardens.

Once the Muddy Buddies have cooled, they are ready to be enjoyed. Serve them in a bowl, and they're perfect for snacking or sharing!