In the bowl of an electric mixer fitted with a paddle attachment, cream together the butter and sugar until light and fluffy.
In a medium bowl, sift together the flour and salt. Add the flour mixture a 1/2 cup at a time to the butter and sugar mixture. Mix on low speed until the dough starts to come together. Shape into a flat disk. Wrap in plastic and chill for 30 minutes.
Roll the dough into a rectangle on a well floured surface, 15-inches by 6-inches by 1/2-inch thick. Cut in 1/2 down the middle lengthwise. Cut into 1-inch by 3-inch pieces. Place the cookies on an ungreased baking sheet. Prick with a fork, and sprinkle with additional sugar if desired. Bake at 325 degrees for 20 to 25 minutes, until the edges begin to brown. Allow to cool to room temperature.
When the cookies are cool, place them on a baking sheet lined with parchment paper. Put the chocolate in a glass bowl and microwave on high power for 30 seconds. Stir with a spoon. Continue to heat and stir in 30-second increments, until the chocolate is melted.
Drizzle or dip 1/2 of each cookie in chocolate. Place them back on the parchment lined baking sheet to cool. You can speed up the process by refrigerating the cookies for about an hour. Store cookies in an airtight container.