Instructions:
- Preheat oven to 250°F (120°C). Line two large baking sheets with parchment paper.
- In a very large mixing bowl, gently combine the Rice Chex, Corn Chex, pretzels, and mixed nuts.
- In a saucepan, melt the butter. Whisk in the brown sugar, vanilla extract, cinnamon, nutmeg, ginger, and salt until the sugar is dissolved and the mixture is smooth. Bring briefly to a gentle simmer, then remove from heat.
- Pour the warm butter mixture evenly over the dry ingredients in the large bowl. Using a rubber spatula, gently fold everything together until all the cereal and pretzels are evenly coated.
- Divide the mixture evenly between the two prepared baking sheets, spreading into a thin, single layer.
- Bake for 45 minutes. At the 22-minute mark, gently toss the mix on the pans using a spatula to ensure even crisping.
- Remove from the oven and let the mix cool completely on the baking sheets to achieve maximum crunch.
- Once fully cool, transfer the mix to a very large bowl. If using, place the powdered sugar in a sieve and dust lightly over the mix, tossing gently to coat.
- Store the finished Holiday Chex Mix in an airtight container at room temperature.