Beat butter at medium speed with an electric mixer until creamy. Gradually add sugar, beating until smooth. Stir in pecans, bourbon, and vanilla until blended.
Stir together flour and next 2 ingredients. Gradually add flour mixture to butter mixture, beating at low speed until blended.
Divide dough in half; flatten each into a disk.
Roll each disk to 1/4-inch thickness between 2 sheets of wax paper.
Transfer dough, in wax paper, to a baking sheet; chill 1 hour.
Preheat oven to 35
Working with 1 portion of dough at a time, remove top wax paper; cut with a 3-inch snowflake-shaped cutter, rerolling dough scraps once.
Place 1 inch apart on parchment paper-lined baking sheets.
Bake at 350 for 14 to 16 minutes or until edges are golden. Cool on baking sheets 1 minute; transfer to wire racks. Cool completely. Store in airtight containers.