Step 1

Preheat the oven to 200 degrees and pour the Chex and popcorn into large bowls.

Step 2

Make the caramel sauce by adding the butter, brown sugar, corn syrup, and salt to a small saucepan. Cook over medium heat, stirring constantly. After the butter is melted, allow the mixture to simmer for 5 minutes, stirring the whole time.

Step 3

Remove the pan from heat and add the baking soda. Stir to mix the baking soda into the other ingredients, then immediately pour the mixture over the Chex and popcorn.

Step 4

Carefully stir the cereal and popcorn until it’s fully coated in the caramel sauce.

Step 5

Spread the mixture evenly over 2 baking sheets and top with Christmas sprinkles, if desired. Place the pans in the oven to bake for 1 hour.

Step 6

When the cook time is up, remove the pans from the oven and allow to cool completely. Top with M&Ms and mini marshmallows, then transfer to a serving bowl or airtight container.