Microwave Oven Peanut Brittle

I love this recipe, the only thing is that you really have to watch it. I find that if I ever leave the room, even for a second, it always gets burnt.

1 1/2 c. dry roasted peanuts
1 c. white sugar
1/2 c. light corn syrup
1 pinch of salt (optional)
1 Tbsp. butter
1 tsp. vanilla extract
1 tsp. baking soda

Grease a baking sheet, set aside. In a glass bowl, combine peanuts, sugar, corn syrup, and salt. Cook in the microwave for 6 minutes on high (keep an eye on it, if you are making more than one batch, lessen the time to 5 1/2 minutes because the microwave gets hot); mixture should be bubbly and peanuts browned. Stir in butter and vanilla; cook 2 more minutes (this is when you really have to watch it, because if it starts turning brown then it is burnt. I lessen the time on this to 1 1/2 minutes when doing more than 1 batch).
Quickly stir in baking soda, just until mixture is foamy. Pour immediately onto greased baking sheet. Let cool 15 minutes, or until set. Break into pieces, and store in an airtight container.