1c butter, softened
1/2 c powdered sugar
1/2 t vanilla extract
2 1/4 c flour
Beat together butter, sugar, and vanilla until well blended. Add flour, one cup at a time, to butter mixture. On a floured surface, roll out dough to 1/4-1/2" thick. With a sharp knife, cut dough into 2" squares or cut into rounds with a cookie cutter. Place on ungreased baking sheet and prick top of cookies with fork. Bake for 25-30 minutes at 325* until bottoms are golden brown and top is light in color. Cool on wire racks. Store in airtight containers.
P.S. I have airbake cookie sheets and the bottoms didn't really get golden brown before the tops were light. Still delicious, though!