This beverage is synonymous with the holidays and our simple recipe makes it a tradition worth bringing back. The addition of cocoa makes it a decadent treat for any guest.
In a large saucepan, whisk together eggs,sugar and cocoa powder until well combined. Whisk in milk. Add cinnamon sticks, nutmeg, mace and cloves; place over medium heat and whisk gently for about 10 minutes or until mixture has small bubbles around the edge of pan and thermometer reaches 160 F (71 C).
Remove from heat and pour through fine mesh strainer into a large bowl. Whisk in rum (if desired) and cover with plastic wrap, directly on surface, and refrigerate for at least 4 hours or up to 2 days.
In a bowl, beat whipping cream until stiff peaks form. Dollop each cup of egg nog with whipped cream and sprinkle with cinnamon or chocolate shavings, if desired.