Preheat the oven to 375 degrees F with a rack positioned in the middle of the oven. Lightly coat a rimmed baking sheet with cooking spray.
Combine the sugar, honey, 3 tablespoons water, the vanilla and 1/2 teaspoon salt in a large heavy-bottomed pot. Cook over medium heat, stirring with a wooden spoon, until the sugar dissolves completely. Add the peanuts and cook, stirring occasionally, until the mixture begins simmering, about 1 minute. Increase the heat to medium high and continue cooking, stirring constantly, until the sugar mixture starts to dry out and clings to the nuts, 2 to 4 more minutes. Pour onto the prepared baking sheet and spread in an even layer.
Bake the nuts until the sugar coating begins melting, about 5 minutes. Continue baking, stirring occasionally, until the nuts are golden brown and glazed in spots, 6 to 8 more minutes. Remove the baking sheet from the oven and stir the nuts to distribute the caramel. Let cool on the baking sheet. Store, covered, at room temperature for up to 1 week.