Combine the sugar, corn syrup, water, salt and butter in a 3.5-qt. sauce pan over medium heat. Bring the mixture to a simmer over medium heat and cover for 1 minute.
Remove lid and cook sugar mixture until it reaches 270°F/132°C on a candy thermometer.
Stir in the nuts and the cayenne pepper and continue to cook until the mixture reaches 295°F/146°C on a candy thermometer.
Remove the pan from the heat and stir in the baking soda (mixture will bubble vigorously).
Quickly pour the mixture onto a nonstick baking sheet and spread out to 1/4-in. thick. Allow the candy to cool and break into pieces.
Store in airtight containers.