Pour 8 cups of rice Chex cereal into two large mixing bowls (4 cups cereal in each bowl). If you aren't going to make half pink with the red food coloring, you can put all of the cereal into one bowl.
Place 1/2 of the peanut butter (1/4 cup), butter (2 tbsp) and the white chocolate chips or white candy melts (1/2 cup) into separate medium microwave-safe bowls. If you are going to make them all white you can put everything together in one bowl.
Microwave the mixture on 50% heat in 30 second increments, stirring after each 30 seconds. Do this until mixture is melted together. Stir in the vanilla extract.
Add about 6 drops of red food coloring to one bowl of peanut butter mixture and stir to combine. You need the mixture to be dark pink so it shows through the powdered sugar. Dark pink candy melts could be used in lieu of the white chocolate chips for the pink mixture instead if you don't want to use food coloring.
Pour each mixture over Chex cereal in the separate bowls and stir with a rubber spatula, taking care not to crush the cereal. Mix until cereal is covered.
Add one cup of powdered sugar to each bowl and stir gently with the rubber spatula to cover. I recommend this method if you are making pink chex mix because the red food coloring mixes better when you stir it in by hand. Alternately you can place powdered sugar in two separate ziplock bags and shake them to cover the cereal.
Put both batches of white and pink Chex into a large mixing bowl.
Melt the pink candy melts in a small microwave safe bowl on 50% power for 30 second increments until it is melted. Dip one side of the white chocolate covered pretzels and set them on waxed paper or parchment paper. Sprinkle with nonpareils or sprinkles and let the dipped side set up.
Now add the M&M's, dipped pretzels and circus animal cookies to the muddy buddy mix and stir gently to combine with a rubber spatula.
Store in a large ziplock bag or separate into individual smaller bags if desired.You can easily double this recipe. This makes a fun and easy edible gift!