In a microwave-safe 8-cup glass measuring bowl, mix sugar and corn syrup until blended. Microwave, uncovered, on high for 3 minutes; stir. Microwave, uncovered, on high 2-1/2 minutes longer. Stir in cashews, cinnamon, cayenne, salt and remaining butter.
Microwave, uncovered, on high for 2 to 2-1/2 minutes or until mixture turns a light amber color (mixture will be very hot). Quickly stir in baking soda and maple flavoring (mixture will foam). Immediately pour into prepared pan, spreading with a metal spatula. Cool completely.
Break brittle into pieces. Store between layers of waxed paper in an airtight container.