Prepare your workspace by lining your sheet pan with parchment paper.
In a heavy duty thick bottomed pot, combine sugar, butter, corn syrup, water, and salt. Don't start cooking yet.
In separate containers, measure out your baking soda, vanilla, and peanuts. Set aside but have them close by.
Cook your syrup slurry over high heat until 308F. This takes approximately 25 minutes from start to finish. The syrup will be a light blonde color.
When syrup reaches 308F, turn off the heat. Add in vanilla, stir.
Add in baking soda, stir until combined but not vigorously. You want to keep the air trapped in the syrup. Fold in peanuts. When you add the baking soda, the syrup will change to a golden hue.
Spread on prepared sheet. Spread the mass to keep it from being thick, but do not press all of the air out.
Cool completely. Break once cooled. Store in an airtight container if not chocolate covering.