Best Sugar Cookies Ever

1 1/2 cups sugar
1 1/2 cups butter, softened
2 eggs
2 T vanilla
4 cups white flour
1 t salt
1 t baking soda
1 t cream of tarter

Frosting:
1 1/2 cups powdered sugar
3 T butter, softened
1 T vanilla
1 T milk
food coloring, optional
sprinkles

In a mixing bowl, combine sugar and butter; beat until creamy.  Add eggs and vanilla; beat well.  Stir together dry ingredients; gradually add to creamed mixture until completely blended.  Chill for 30 minutes.  On a lightly floured surface, roll dough to a 1/4 in. thickness.  Cut with holiday cutters dipped in flour.  Using a floured spatula, transfer cookies to ungreased baking sheets.  Bake at 350 for 10-12 minutes.  Cool on wire racks.  For frosting, combine sugar, butter, vanilla and milk; beat until creamy.  Thin with additional milk to desired spreading consistency if necessary.  Add a few drops of food coloring if desired.  Spread frosting over cookies and decorate with colored sugar.  Yield: 7 dozen (2 1/2 in. cookies).