You’ll need a candy thermometer for this so that you don’t mess things up (literally). Line a baking tray with parchment paper.

Mix the water sugar and corn syrup together in a heavy pot and place on stove top and heat on medium heat, stirring constantly. Bring to a boil. Once the temperature reaches 290 degrees stir in the butter, baking soda, and vanilla. Add in peanuts, stir and then spread out the mixture onto the baking sheet spreading everything out so that the nuts are evenly distributed.

Let cool down for about an hour. Once cooled break the brittle apart using your hands. You can use the parchment paper to hold the brittle as you break it so that your hands don’t get sticky.