In a glass bowl, stir together the sugar, corn syrup, peanuts, cinnamon, and cayenne pepper until thoroughly blended. Microwave on high for 6 minutes. Slowly stir in the butter, and microwave an additional 30 seconds.
Very carefully remove bowl from the microwave as the contents will be extremely hot. Gently stir in baking soda until mixture becomes light and foamy. Turn batter out onto a lightly oiled cookie sheet, scraping sides of bowl with a rubber spatula. Allow brittle to cool for 1 hour, then break into pieces.
