Peanut Brittle

1 1/2 tsp baking soda
1 tsp water
1 tsp vanilla
1 1/2 cups sugar
1 cup water
1 cup light corn syrup
3 T butter
1 lb unsalted Spanish peanuts

Heat oven to 200 F. Grease cookie sheet with butter; keep warm in oven. In small bowl, mix baking soda, 1 tsp water and the vanilla; set aside.  In 3-quart saucepan, mix sugar, 1 cup water and the corn syrup.  Cook over medium heat about 25 minutes, stirring occasionally to 240 F on candy thermometer.  Stir in butter and peanuts.  Cook over medium heat about 13 minutes stirring constantly, to 300 F.  Immediately remove from heat.  Quickly stir in baking soda mixture until light and foamy.  Pour onto cookie sheet and quickly spread about 1/4 inch think with buttered spatula.  Cool completely and then break into pieces.