01 -
Preheat oven to 350°F (175°C). Prepare a parchment-lined baking sheet and set aside.
02 -
In a medium saucepan over low heat, melt unsalted butter. Stir in brown sugar and heat until mixture is fully combined and begins to bubble, about 2-3 minutes.
03 -
Remove saucepan from heat. Stir in vanilla extract and salt until blended.
04 -
Place Chex cereal in a large mixing bowl. Pour warm toffee mixture over cereal, gently folding until pieces are evenly coated. Add chopped nuts if using, and toss to combine.
05 -
Evenly spread coated cereal mixture onto the prepared baking sheet. Bake for 15 minutes, stirring gently halfway through to ensure uniform toasting.
06 -
Remove from oven and allow Chex mix to cool completely on the baking sheet. Once cooled, transfer to a serving bowl or airtight container.