Line a large baking sheet with wax or parchment paper.
In a medium heavy-bottomed saucepan, melt butter over medium heat. Add brown sugar, cream, corn syrup, and salt; bring to a boil, stirring frequently. Cook for 1 minute, stirring frequently. Remove from heat. Add confectioners’ sugar and vanilla; beat with a mixer at low speed until smooth. Stir in peanuts. Let stand, stirring occasionally, until mixture is thick enough to drop with a spoon, about 5 minutes.
Drop peanut mixture by heaping tablespoonfuls 2 inches apart onto prepared pan. Immediately sprinkle with sea salt. Let stand until firm, 3 to 4 hours. Gently remove from paper. Store in an air-tight container.
Recipe by Taste of the South at https://tasteofthesouthmagazine.com/peanut-pralines-2/