In a medium-sized pot, cook the sugar, corn syrup, and water until the mixture reaches 285 degrees. Stirring occasionally.
Add the salted peanuts and butter. Stirring constantly until the mixture reaches 295 degrees and is slightly golden in color.
Remove the pot from the heat.
Working fast, add the vanilla and baking soda until the mixture is completely combined.
Pour the mixture onto a cookie sheet lined with a silicone liner. Working quickly, spread the mixture out with an offset spatula
Place the pan on a cold surface until the brittle is completely cool. Break into pieces and store in an airtight container.
