Sweet, spicy and crunchy--this snack has it all!
Preheat oven to 300 degrees. Line a rimmed baking sheet with parchment paper. Lightly coat parchment and a large bowl with nonstick spray. Add popcorn to bowl. Set baking sheet aside.
Bring sugar and ¼ cup water to a boil in a medium saucepan over medium-high heat, stirring to dissolve sugar. Boil, swirling pan occasionally, until caramel is a deep amber color, 10-12 minutes. Remove from heat. Stir in hot sauce and butter (mixture will bubble vigorously). Return to a boil and cook another 3 minutes.
Remove from heat. Stir in salt, baking soda and cayenne. Working quickly (and carefully-caramel will be very hot), pour caramel mixture over popcorn and toss to coat. Spread out popcorn on prepared baking sheet and bake, tossing once, until dry, 15-20 minutes. Let cool.