Add sugar, softened butter, and vanilla extract to the bowl of a stand mixer. Beat using the paddle attachment until combined and fluffy.
If your flour is not pre-sifted, sift it using a fine mesh sieve. Then whisk together flour, and salt in a mixing bowl and add to the beaten butter mixture. Mix until a dough forms.
Scrape the dough out of the bowl onto a piece of plastic wrap, shape into a disk or a rectangle. Refrigerate for at least 30 minutes to 1 hour.
When the dough is ready, take it out of the refrigerator and roll dough to between 1/4” - ½” thick. Cut out cookies with a 2” round or fluted cookie cutter. Re-roll the scrap dough and cut out more cookies until finished. This will yield about 32 cookies. Place the cookies in a container in layers with parchment paper in between and freeze while the oven is preheating.
Preheat the oven to 350°F.
When the oven is ready, place cookies on a parchment lined baking sheet 1 to 2 inches apart. Sprinkle granulated sugar over the top of cookies generously and bake for 11 - 15 minutes until the edges are starting to turn light brown.
Remove from the oven, let cookies cool on the baking sheet for 5 minutes before transferring to a wire rack to cool completely
To make the topping, melt chocolate in a heatproof glass bowl over a small pot of simmering water over medium low heat, double boiler style.
Cover the cookies half way with melted chocolate by dipping them into the bowl or spooning the chocolate over the cookies. Let the excess chocolate run off back into the bowl and place the cookies back on the parchment lined baking sheet to harden.
If using sprinkles, add them as soon as you place the cookies on the baking sheet before the chocolate hardens.