Preheat oven to 325°F and line insulated baking sheets with parchment paper or silicone mats.
In a medium bowl, cream together butter and granulated sugar until creamy. Add vanilla extract beat until incorporated.
With mixer at low speed, beat in flour and finely chopped pecans until dough comes together and all ingredients are incorporated.
Shape dough into 1-inch balls (about a level tablespoon). Place 1-inch apart on prepared baking sheets.
Bake 16-18 minutes or until very lightly browned.
Cool 5 minutes on pan then roll in powdered sugar while cookies are still warm.
Allow to cool completely.
Roll cookies in powdered sugar again when cool.
Notes
These cookies can be kept at room temperature for a day or in the refrigerator for 3-4 days.
Snowball cookie dough can be made up to three months ahead of time. Make up to the step right before rolling out the dough balls. Wrap the dough in plastic wrap, then wrap in freezer paper and freeze until ready to bake. Thaw dough, roll into balls and proceed with recipe.