Line two large baking sheets with parchment paper and set aside.

Pour the Chex cereal into a very large mixing bowl.

Add the mini pretzels and gently toss everything together until evenly mixed.

Break the Oreo cookies into bite-sized pieces and set them aside.

Place the Andes mint baking chips in a medium heavy-bottomed saucepan.

Pour in the sweetened condensed milk and heat over very low heat, stirring constantly until the mint chocolate melts and the mixture becomes smooth and creamy.

Remove the saucepan from the heat and allow the melted chocolate mixture to cool for 2 minutes.

Slowly drizzle the warm mint chocolate mixture over the Chex cereal and pretzels.

Using a large spatula, gently toss everything together until the cereal and pretzels are evenly coated.

Add the broken Oreo cookies and carefully fold them into the chocolate-coated mixture.

Spread the mixture evenly across the prepared baking sheets.

Place the baking sheets in the refrigerator for 20 to 30 minutes until the chocolate coating begins to firm up.

Remove the mixture from the refrigerator and gently break apart any large clusters.

Transfer the coated cereal mixture into a large bowl and sprinkle the powdered sugar over the top.

Toss gently until the pieces are lightly coated with powdered sugar.

Add the red and green holiday M&M’s and gently mix them throughout the snack mixture.

Return the mixture to the refrigerator for another 15 minutes until completely set.

Transfer the Christmas Crack Mix into a large festive serving bowl.