1) Line a baking sheet with parchment paper or a silicon mat, or just a thin layer of vegetable oil.
2) In a small bowl, sift baking soda, sea salt and cayenne. Set aside.
3) In a medium-sized, heavy saucepan, heat the butter, sugar and water over medium-high heat until it just begins to turn golden, about 3-5 minutes.
4) Add peanuts and start stirring, coating with sugar mix.
5) After a few minutes the sugar will ‘seize’ and turn grainy. No problem, just keep stirring!
6) Stir for about 7 minutes, until the sugar melts back into a golden color. Keep stirring and try to coat nuts evenly.
7) Remove pot from heat and stir in baking soda mixture as fast and evenly as you can.
8) Pour the nuts onto the prepared sheet and spread out into a single layer- trying to smooth out clumps.
9) Cool completely and break into pieces. Brittled nuts will keep in airtight container for up to 2 weeks.