How to Make It
Combine sugar, corn syrup, butter, and vanilla extract in an Instant Pot. Stir to combine. Turn Instant Pot to Sauté setting on Low, stirring occasionally, until sugar mostly dissolves; set timer to 30 minutes.
Turn Sauté setting to Normal, and cook, stirring occasionally, until syrup mixture reaches a rich, caramel color and all sugar is dissolved, 15 to 20 minutes.
Stir baking soda into mixture, 1 teaspoon at a time, until combined. Bring to a boil, and stir in peanuts.
Pour mixture onto a baking sheet lined with parchment paper, spreading out towards edges of pan. If desired, sprinkle with sea salt. Let cool for about 1 hour. Crack into pieces.