In large bowl, beat butter and sugar with electric mixer until light and fluffy. Beat in eggs and vanilla; mix well. Stir in flour; mix until blended. If desired, stir or knead icing color into all or part of dough.
Divide dough into 2 pieces; roll each portion into logs, with about 2-inch diameters. Roll log in colored sugars or holiday sprinkles. Wrap with plastic wrap; refrigerate at least 2 hours.
Preheat oven to 375ºF. Remove plastic wrap and cut each log into 1/4-inch-thick slices; place on ungreased baking sheet. Bake 10 to 12 minutes or until light golden brown. Cool 2 to 3 minutes on cookie sheet on cooling grid. Remove from sheet and cool completely.