Before you start, place a metal cookie sheet in a 200 degree F. oven to warm.
Although this is a pretty easy recipe, it requires you to move fast, so all the ingredients should be measured out and easily accessible before you get started.
Mix corn syrup and sugar in a large glass bowl, or measuring cup, and microwave on high for two minutes.
Remove bowl from the oven and stir thoroughly. Microwave for two more minutes.
Stir in peanuts and microwave for three additional minutes.
Add half the butter, vanilla, and all the spices, except the baking soda. Stir to combine all the ingredients and microwave for two additional minutes. During this time, remove the warmed pan from the oven and butter with the reserved teaspoon of butter.
After two minutes have elapsed, sprinkle the baking soda over the peanut mixture. Mix vigorously, until the mixture becomes lighter in color and foamy.
Quickly pour out the mixture over the warmed pan. Spread by tilting the pan back and forth. Avoid spreading with a spatula, as this will pop all the tiny bubbles that make the brittle airy and light.
Cool completely before breaking into pieces. Enjoy!