Pro Tip: Be creative with your Bûche de Noël. It can be assembled with one limb on the side or with two limbs (one on the side and top). Simply cut the 3 to 4 inch piece of cake in half to form top. Ganache may be made up to 2 days ahead and refrigerated. Remove from refrigerator, and let stand at room temperature for 45 minutes to 2 hours before beating.