Preparation

1. Preheat oven to 200°F.
2. Place a 3-feet length of aluminum foil on a counter or work surface near the stovetop, shiny side up. Using a paper towel, grease foil liberally with vegetable oil.
3. Grease the sides of a 6-quart saucepan with butter and set aside.
4. Arrange peanuts on a rimmed baking sheet in a single layer and place in the oven.
5. Meanwhile, add sugar, corn syrup, and water to the buttered saucepan. Place over medium-high heat and stir with a long-handled wooden spoon until sugar has dissolved and mixture comes to a boil.
6. Place a candy thermometer in the pan and let mixture boil over medium heat without stirring until temperature reads 275°.
7. Melt the tablespoon of butter in the microwave or a separate saucepan and set aside.
8. Once thermometer reads 275°, add the warmed peanuts to the mixture and continue to cook, stirring frequently, until temperature reaches 300°. The mixture will start to darken, but if it starts to smell burnt, just lift pan off the heat and stir to cool it a bit.
9. Working very quickly, remove the pan from the heat and stir in the melted butter and baking soda. Stir quickly for just 2-3 seconds until mixture becomes pale and foamy. It should rise to the top of the pan. Don't wait for the foam to settle!
10. Pour foamy mixture onto the aluminum foil, but do not smooth it out or you will lose the honeycomb texture.
11. Let sit until cool and crisp, about 30 minutes. Once cool, use a wide metal spatula to turn the brittle over. Blot any moisture with a paper towel.
12. Break brittle into pieces and enjoy!