- 5 quarts popped popcorn
- 2 cups unsalted cashews
- 2 cups packed brown sugar
- 1/2 cup light corn syrup
- 1 cup unsalted butter
- 1 teaspoon salt
- 1/4 teaspoon cream of tartar
- 1 teaspoon baking soda
- Preheat oven to 200 degrees F (95 degrees C).
- Mix popcorn and cashews together in a large roasting pan.
- Combine brown sugar, corn syrup, butter, salt, and cream of tartar in a large saucepan. Bring to a boil, stirring constantly, until a candy thermometer inserted into the middle of the syrup, not touching the bottom, reads 260 degrees F (127 degrees C), 6 to 8 minutes.
- Remove syrup from heat; stir in baking soda. Pour over popcorn and cashews; stir to coat.
- Bake in the preheated oven, stirring every 20 minutes, until sugar mixture has baked and caramelized onto popcorn and cashews, about 1 hour. Spread cashew caramel corn onto a parchment paper-lined baking sheet to cool. If desired, form into balls while still warm.