In large bowl, cream together butter, sugar, vanilla, and salt until well-blended. Add flour and soda. Mix well until flour is completely incorporated.
Divide dough into three parts and shape into three logs, about twelve inches long. Wrap well in parchment paper or waxed paper.
Refrigerate dough at least overnight or up to a week. It can also be frozen for up to a month. Thaw frozen dough on the counter for one hour before slicing.
When ready to bake cookies, preheat oven to 375°F.
With a sharp knife, cut logs into ¼ inch slices. Place on cookie sheet 2 to 3 inches apart and bake for 10 to 12 minutes or until lightly browned.
Cool on baking sheet five minutes and remove to wire rack to cool completely.
Notes
Before baking, sprinkle the cookies with colored sugar to add a colorful touch for the holidays.
For a more traditional sand tart, press almond slices or a pecan half into the cookie before baking. Brush the tops with an egg wash (one egg white, lightly beaten) and sprinkle with cinnamon sugar.
Cookie dough will keep in the refrigerator for 1 week or in the freezer for up to a month. Thaw slightly before slicing.