1. Preheat oven to 350º.
2. Beat cake mix, eggs, buttermilk, water, oil and vinegar in mixer bowl until smooth.
3. Turn off the mixer (see note) and add the food coloring. Beat 2 minutes at high speed.
4. Grease and lightly flour a 12-cup bundt pan. Pour the batter into the prepared pan.
5. Pour the batter into the prepared pan. Place the baking pan on the middle rack of the oven, and bake 30-40 minutes until cake tester comes our clean.
6. Let the cake cool at least 30 minutes and then remove from the pan onto a serving plate. (The unfrosted cake may be stored, tightly covered with plastic wrap, at room temperature for 24 hours.)
7. To frost the cooled cake, mound the cream cheese frosting over the top third of the cake and let it drift down the sides (giving it a snow-capped look). A portion of the deep-red cake will show underneath.
8. Garnish the top by arranging fresh cranberries and dried bay leaves to look like holly, if desired. Serve at once or refrigerate, covered, until ready to serve, up to 24 hours. Leftovers may be refrigerated up to three days.