In a mixer with a paddle, mix butter and sugar on medium speed until fluffy. Add flour and mix for 1 minute. Fold in pecans and salt and mix for 1 minute.
Divide the dough into two balls and wrap them in plastic. Refrigerate for ½ hour.
Preheat the oven to 350°. Grease a cookie sheet. Shape dough into quarter-sized balls and bake for 16 minutes. The cookie should be brown on the bottom and pale on top.
Cool slightly, roll in powdered sugar, and serve. After fully cooled, store in an airtight container.