In a stand mixer (paddle attachment), combine butter, confectioners sugar, vanilla and salt, blend until smooth. Add flour gradually and mix on low until just combined. Stir in jimmies using a spoon or your hands. Form dough into a 12- to 14-inch-long round log, wrap in plastic wrap and freeze until firm: at least 30 minutes.

Preheat oven to 350 degrees F. Cut dough into 1/4 inch thick slices. Roll edges in red and green sugar. Bake on parchment paper lined baking sheets for 15 to 18 minutes or until cookies are light golden brown around the edges. Cool for a few minutes on trays before removing cookies to wire racks to cool completely.