Hot Cocoa Christmas Puppy Chow

Gently combine the Chex cereal and pretzels in a big bowl or airtight container with a lid.

Next, fill a pot with about 1-2 inches of water and bring it to a gentle simmer. Add the chocolate chips and unsalted butter cubes to a heatproof mixing bowl. Set the bowl over the simmering water, ensuring that the water doesn't touch the bottom of the bowl. Stir constantly, just until the chocolate mixture is smooth and completely melted.

Remove the chocolate mixture from the heat. Stir in the marshmallow fluff and salt until smooth. The mixture will be a bit fluffy. Pour the chocolate-marshmallow mixture over the cereal and pretzels. Stir very well until the snacks are completely covered in chocolate. Then, break up any big clumps with a spoon or rubber spatula.

Let the snack mix sit for about 5 minutes. Meanwhile, whisk the powdered sugar and hot cocoa mix in a medium bowl. Pour half of the powdered sugar-cocoa mix over the puppy chow. Cover and shake rapidly until the snack mix is well-covered. Repeat with the other half of the powdered sugar-cocoa mix.

Spread the puppy chow on a big sheet pan and let it set completely, about 30 minutes. Then, stir in the mini marshmallows, M&Ms, and nonpareil dark chocolates. Store in an airtight container for 2-3 weeks.