Instructions

1. Place the marble slab, or inverted baking sheet, on the work space.  Generously brush oil over the entire surface of the marble slab, or inverted baking sheet.
2. In a small bowl, sift together the baking soda and salt.  
3. In a 4-quart, deep, heavy-bottomed saucepan, combine the water, corn syrup, and sugar. Stir over medium-low heat until the sugar dissolves, about 10 to 12 minutes.
4. Once the mixture is clear and begins to boil, increase the heat to high and stop stirring.
5. Place a candy thermometer in the mixture holding it with a mitt to protect your hand. Cook until the syrup registers 265°F on the thermometer, about 8 to 10 minutes.
6. Add the nuts and gently stir to incorporate.
7. Continue cooking, stirring occasionally, until the mixture reaches the hard-crack stage, 305° to 310°F, about 5 minutes longer.
8. Immediately remove the pan from the heat.
9. Stir in the softened butter, the vanilla extract, and then the baking soda and salt. The mixture will soon start to foam.
10. Stir just until the mixture foams evenly and immediately pour it onto the oiled marble slab, or inverted baking tray.
11. The mixture should spread to about 14 inches in diameter.
12. Slip the oiled spatula under the hot candy to loosen the edges and bottom.
13. Put on the gloves and as soon as the candy is firm enough on the bottom to be picked up (the top won’t be hard yet), lift the edges and turn the entire piece of brittle over. With gloved hands, stretch the brittle to extend it so it’s as thin as you can get it, about 17 inches in diameter.
14. Allow the candy cool undisturbed for at least 1 hour and then break it into small pieces.
15. Store the brittle in airtight containers.

Note:  Peanut Brittle can be held for up to 10 days.