Directions

1. Sift together flour, salt, and baking soda, and set aside. In the bowl of an electric mixer fitted with the paddle attachment, beat together butter and sugar on medium speed until light and fluffy. Add egg and vanilla, and beat until well combined. Add peanut butter, and beat until smooth. Add flour mixture, and beat on low until combined. Wrap dough in plastic wrap, and transfer to the refrigerator to chill several hours.
2. Preheat oven to 350 degrees. Have ready two baking sheets lined with parchment paper. Form each cookie into a ball using 1 level tablespoon of dough and, with a finger, press and shape to form a 1 3/4-inch slightly squared circle. Place cookies on the prepared baking sheets, about 1 inch apart. Dip a fork into flour, and tap off the excess. Press tines of fork into four edges of each cookie. Place cookies in freezer to chill for 15 minutes.
3. Bake until golden, about 15 minutes, rotating halfway through. Remove from oven, and place on a wire rack until completely cool.
4. Melt chocolate until smooth, either over a gently simmering double boiler or in the microwave in 20-second increments, stopping to stir with a rubber spatula after every 20 seconds. Let chocolate stand until cool to touch.
5. Fill a paper cornet (or a resealable plastic bag with a bottom corner snipped) with chocolate. Pipe chocolate into the indentations left by the fork. Set aside in a cool place to allow chocolate to set.