Preheat oven at 325 degrees F.
Combine flour and pecans, set aside. Beat butter and sugar in a large bowl with electric mixer on medium speed until light and fluffy. Blend in vanilla.Gradually add flour mixture, mixing until well blended.
Roll dough into 36 balls, each about ¾ inch in diameter (bonus: they are teeny-tiny si you can feel less guilt). Place 2 inches apart on ungreased baking sheets.
Bake 20 minutes or until edges are lightly browned. Cool completely on wire racks.
Grate white chocolate into a shallow bowl; set aside. Microwave semi sweet chocolate in a microwaveable bowl on medium 1 ½ minutes or until chocolate is almost melted. Stir until chocolate is completely melted. Dip each cookie halfway in the melted chocolate, then in the grated white chocolate to create a snowy appearance. Let stand until chocolate is firm.