• Make sure all ingredients are ready and measured out before starting. Some steps require quick actions, so this will help the process.
• Preheat the oven to 170°F.
• Grease a 10x15 jelly roll pan or cookie sheet with at least 1-inch tall sides. Set aside.
• In a large pot over medium heat, bring sugar, corn syrup, salt, and water to a boil. Stir until the sugar is dissolved. When the liquid looks clear, that indicates the sugar has dissolved.
• While mixture is heating up, add the jelly roll pan to the preheated oven so it can warm up.
• Add a candy thermometer to the sugar mixture. When the temperature reads 250°F, stir in peanuts. Cook on medium-low heat at a steady boil until the temperature reaches 300°F (takes about 10-13 minutes).

  If you don't have a thermometer, drop a small amount of the candy mixture into a bowl of cold water, if it separates into hard and brittle threads, it's ready.
• Once the mixture reaches 300°F, this is the fast part. Remove from heat and immediately stir in butter, baking soda, and vanilla.

  Working quickly, pour back and forth onto the cookie sheet. Using oven mitts, move the pan around until mixture spreads out (do not spread with a knife or spatula).
• After pouring/spreading, allow it to sit at room temperature for 10 minutes to let cool. Then place in the refrigerator for another 20-30 minutes.

NOTE:

• When the baking soda is added, the reaction causes the brittle to lighten up in color, but as it cools, it will return to a golden beige color.

  This recipe will not cover the entire surface of the 10x15 jelly roll pan. It will cover about half of the pan. If you would like to fill up the entire 10x15 jelly roll pan, we suggest doubling this recipe.