Preheat oven to 250 degrees F.
In a large mixing bowl, melt butter. Whisk in sugar, vanilla, and pinch of sea salt until it’s dissolved.
Add cereal, peanuts, and pretzels to bowl and toss to combine.
Spread on a large baking sheet and bake for 1 hour, stirring every 15 minutes until golden brown.
Sprinkle with flaky sea salt and let cool completely.
Store in an airtight container for up to 2 weeks.
