Secure a candy thermometer to the side of a large heavy-duty pot. Generously grease a large, rimmed baking sheet or line it with parchment paper or a Silpat™ baking mat, as shown. Set aside.

Add sugar and water to the pot and stir to combine. Pour in the corn syrup, and heat over medium heat, stirring occasionally with a wooden spoon, until the sugar is thoroughly dissolved, approximately 2-3 minutes.

Bring the mixture to 250°F on the candy thermometer, then stir in the roasted peanuts until thoroughly combined.

Continue heating the peanut mixture until it reaches 300°F, stirring frequently. Remove from heat and immediately stir in the vanilla extract, cinnamon, nutmeg, baking soda, salt, and butter until combined. Immediately pour the mixture onto the prepared baking sheet and spread into an even layer with a butter or pastry knife.

Set aside and cool completely until the mixture is completely hardened and breaks easily into chunks, approximately 30 minutes to one hour. Serve immediately or store in an airtight container at room temperature for several weeks. Enjoy!