Begin by pouring the eggnog into a large mixing bowl. Add the vanilla extract and, if you choose to use it, the maple syrup. Whisk the mixture thoroughly until all ingredients are well combined and smooth.
Carefully pour the eggnog mixture into serving glasses, filling each glass to about halfway for the perfect balance of flavors.
Gently pour the sparkling water over the eggnog mixture in each glass. This will create a delightful fizz; pour slowly to retain the bubbles and avoid overflow.
For a rich and creamy finish, add a generous dollop of whipped cream on top of each drink, creating a beautiful contrast against the eggnog.
Sprinkle a light dusting of freshly grated nutmeg over the whipped cream for a festive flair and to enhance the flavor profile.
If you like, insert a cinnamon stick into each glass not only for stirring but also to infuse a warm, aromatic essence into your drink.
Notes
Serve on a decorative tray with festive napkins for an elevated presentation.