Prepare a baking sheet by covering it in parchment paper and spraying it with nonstick cooking spray. Set aside.
In a 2-quart saucepan over medium-high heat, bring the water, corn syrup, and white sugar to a boil while stirring regularly. When the mixture comes to a boil, reduce heat to medium and continue cooking until the mixture turns a golden brown color. This will take about 20 minutes.
Remove the saucepan from the heat and quickly stir in the butter, peanut butter, baking soda, and vanilla. When the mixture foams up, quickly stir in the peanuts.
The peanut brittle will quickly begin to set, so pour the mixture onto your prepped baking sheet and leave on the counter to harden. This will take about an hour.
Once the peanut brittle has hardened, break it into pieces, serve, and enjoy!
Notes
This buttery peanut brittle recipe will work with peanut butter or any other nut butter.
You can substitute other nuts for the peanuts if you like. Cashews are a delicious option, especially if you use cashew butter instead of peanut butter!