Microwave Peanut Brittle

Mix sugar, salt and syrup and cook uncovered in the microwave on high for 4 minutes. (Use a deep microwaveable dish). Stir and add peanuts; cook on high for 4 more minutes. Add butter and vanilla and stir into mixture. Cook for 2 more minutes on high. Remove from microwave and add baking soda. Stir quickly until mixture turns a darker color. Pour immediately onto a greased cookie sheet. Spread with 2 forks. Let cool and harden, then break into pieces.