Peanut Butter and Jelly Buttons

Heat the oven to 350 degrees F. Line baking sheets with parchment paper. In a large bowl, whisk together the flour, baking soda, and salt. Using an electric mixer, beat the butter and sugar in a large bowl until light and fluffy, about 2 minutes. Beat in the peanut butter, then the egg and vanilla. Reduce the mixer speed to low and gradually add the flour mixture, mixing just until incorporated. Place the peanuts in a shallow bowl. Roll the dough into 3/4-inch balls (about a level teaspoon each) and coat with the chopped nuts. Transfer the balls to the prepared baking sheets, spacing them 2 inches apart. With a floured finger, make an indentation in the center of each ball, making sure not to go all the way through. Fill each cookie with 1/4 teaspoon jam. Bake, rotating the positions of the pans halfway through, until the cookies are puffed and starting to brown lightly around the edges, 8 to 10 minutes. Let cool on the baking sheets for 5 minutes, then transfer to a wire rack to cool completely.