These Girl Scout cookies are shortbread cookies with a layer of chocolate on the bottom.
In a medium bowl, use an electric mixer to cream butter and sugar until light and fluffy. Add vanilla, mix and scrape down the sides of the bowl. In a separate medium bowl, combine the flour and salt. With the mixer on low, begin adding the flour to butter mixture. Keep mixing until dough just comes together. Wrap dough into a disc and chill for at least 30 minutes in the refrigerator.
Preheat oven to 350 degrees.
Lightly flour a clean surface and roll dough out dough until 1/8 inch thick. Use a 2-inch round cookie cutter to form cookies.
Place cookies onto a parchment-lined baking sheet and chill in the refrigerator for 30 minutes. Bake cookies for 20 minutes or until the cookies begin to brown. Transfer cookies to a cooling rack.
Melt chocolate in the microwave or in a double-boiler. Dip one side of each cookie in the melted chocolate and place onto a parchment-lined baking sheet, chocolate side up. Allow chocolate to set, about 1 hour.