Grease a large cookie sheet or baking pan with butter and spread the lightly salted peanuts evenly across the pan.

In a mixing bowl, scoop out the Kraft Marshmallow Creme and set aside.

In a heavy-bottomed saucepan, combine the light corn syrup and sugar. Heat over medium-high, stirring constantly until it reaches a rolling boil.

Once boiling, attach a candy thermometer and bring to 290°F (soft crack stage) without stirring.

Remove from heat and let sit undisturbed for 2 minutes.

Carefully pour the hot syrup mixture into the bowl containing the marshmallow creme and stir quickly until smooth. Add melted butter, vanilla extract, and salt, stirring until combined.

Pour the creamy candy mixture over the peanuts and spread evenly to coat.

Let the mixture set at room temperature for about 3 hours or refrigerate for faster setting.

Once set, cut into squares with a sharp knife and wrap in waxed paper if desired.