Preheat the oven to 350ºF. Line a baking sheet with parchment paper or a silpat.
In a large bowl thoroughly combine all ingredients. Spread in a thick layer on the prepared baking sheet.
Bake 30-40 minutes. After the first 15 minutes, gently flip/stir to evenly cook. If you like big clusters, try to keep it packed together. Continue to flip every 10 minutes.
Remove from the oven when lightly browned. It will continue to crisp up as it cools.