Before you begin, check your microwave power. (Mine was written at front when you open the door.) The time directions in this recipe for microwaves with 1000Watts.
Measure and prepare all the ingredients before moving forward.
Spray a baking sheet with non-stick spray.
In 1-quart microwave-safe bowl with a lid (stay away from plastic container though, I prefer a glass bowl), combine peanuts, sugar, salt and corn syrup.
Cover the bowl and microwave the mixture for 3 minutes. (TIP: If you don’t cover the mixture, it’ll get burnt.) Take it out and give it a nice stir.
Take it out and give it a nice stir.
Then cover and microwave for another 3.5 minutes. Take it out and stir in margarine and vanilla extract.
Cover and microwave again for 2.5 minutes. Take it out and add baking soda.
Quickly stir, as the mixture foams. And pour the mixture onto the prepared baking sheet.
Using 2 forks, spread it out into even layer.
Immediately, sprinkle semi-sweet chocolate chips over the hot brittle and let it stand for a minute. Then using a spatula, spread it into even layer.
If you want swirled look, sprinkle white chocolate chips and let it stand for a minute, or until softened. Then using a toothpick, swirl white chocolate chops into semi-sweet chocolate layer.
Let it cool and harden, about 30-45 minutes. Store in a ziplock bag for up to a week.