Combine the peanuts, cinnamon, cayenne, and salt in a small bowl.
Set the mixture aside.
Brush the inside of a medium-sized heavy saucepan with vegetable oil.
This will prevent sticking.
Add sugar and water to the saucepan.
Cook over high heat, stirring occasionally.
Bring the mixture to a boil.
Cover and let it cook for 3 minutes without stirring.
This helps the sugar dissolve properly.
Remove the lid and continue cooking until the sugar turns to a deep amber color.
Stir in the peanut mixture until evenly coated.