In 1 1/2 quart casserole, combine sugar and syrup.
Microwave on high for 3 minutes.
Add peanuts. (May Substitute Almonds Or Cashews For The Peanuts).
Microwave on high 4-5 minutes, until mixture is light brown, stirring every 2 minutes.
Add butter and vanilla; stir well.
Add baking soda and gently stir until light and foamy.
Pour mixture onto lightly greased cookie sheet.
Let cool 30 minutes to 1 hour. When cool, break into small Pieces.