In a stand mixer equipped with a paddle attachment, cream together the butter, sugar, and salt until the mixture becomes light and fluffy. Gradually add the egg yolks while the mixer is running, making sure to scrape down the sides of the bowl to ensure even mixing.
Pour in the vanilla extract and continue to mix. Slowly incorporate the flour into the mixture, blending until everything is well combined.
Shape the dough into a log, wrap it tightly in parchment paper or plastic wrap, and chill it in the refrigerator for a minimum of one hour. To prevent the dough from flattening on one side, you can place it inside an empty cardboard paper towel roll during refrigeration.
Once the dough is fully chilled, sprinkle sanding sugar onto a clean surface. Unwrap the dough and gently roll it in the sugar until evenly coated. Using a sharp knife, slice the dough into even rounds.
Arrange the slices on a baking sheet lined with parchment paper. Bake at 350°F for 10-12 minutes, or until the edges just begin to turn golden brown.