In a food processor, pulse pecans until they are finely ground. Then set them aside to use later.
Make DoughIn a large bowl, beat butter, sugar and salt at medium speed with an electric mixer until the mixture is creamy. This should take about 1 minute.
Add egg yolks, one at a time, mixing well after each addition. Add vanilla and mix well.
Add the flour and the finely ground pecans. Mix until just combined.
Press the dough into a single disc, wrap it in plastic wrap and refrigerate it for at least 2 hours. The dough can be left overnight in the refrigerator if need be.
Make Dough.When ready to bake, preheat the oven to 375°F.
Remove dough from the refrigerator. Let dough sit at room temperature for about 5 to 10 minutes, until it’s slightly softened.
On a lightly floured surface, roll into dough logs and then continue to roll the dough to reduce thickness, until the dough is ¼ inch thick. If the dough cracks, just press it back together.
Cut the dough into 2 1/4 inch rounds and place them on an ungreased baking sheet.
Sprinkle dough with white sparkling sugar. (optional).
Bake cookies for 10 to 12 minutes or until they’re golden light brown around the edges.
Remove the baking sheet from the oven and place onto a cooling grid.
Allow cookies to cool on the baking sheet for 5 minutes then transfer directly to the rack to cool completely.