this is the martha stewart recipe, & it's the best i've ever found.
2 cups butter, room temperature
3 cups sugar
2 large eggs
1 teaspoon vanilla
1 1/2 teaspoon salt
5 cups flour
1. beat together butter & sugar on medium-high speed until light & fluffy.
2. add eggs, vanilla, & salt. mix until combined.
3. on low speed, incorporate flour in two batches.
4. divide dough in half, & wrap both halves in plastic wrap. chill for at least 2 hours.
5. roll out to 1/4" thick, & cut to desired shape.
6. bake on 350 for 10-12 minutes.