Spray a cookie sheet with nonstick baking spray. Line that cookie sheet with parchment paper.
Spray the parchment paper with nonstick baking spray. Add water, corn syrup, and white sugar to a saucepan.
Stirring often as you bring the ingredients to a boil. Continue stirring until it becomes a golden brown. (About 20 minutes)
Remove the saucepan from the stove. While the corn syrup mixture is still boiling add the butter, peanut butter, baking soda, and vanilla.
Use a rubber spatula to mix all of the ingredients. Once this mixture starts to foam, stir in the peanuts until they are completely covered.
Immediately pour this onto the parchment lined cookie sheet.
Spread the mixture on the cookie sheet in a ¼ inch layer. Set it aside on the counter. It will take an hour to firm up.
When the brittle hardens break it into pieces.