Spread the pecans out in a single layer on a parchment-lined baking sheet. Bake for about 8-10 minutes or until fragrant and browned.
Pulse until nuts are ground. Cream the butter, granulated sugar, and brown sugar until fluffy. Stir in egg yolks, flour, salt, and vanilla extract.
Divide the dough in half and place one half on plastic wrap. Roll and shape into a log. Repeat with the other half. Chill in the fridge for 1-2 hours.
Remove the plastic wrap, slice the dough into rounds, and place a pecan half on each cookie. Bake for 20 minutes at 325℉/163℃.