In a spacious mixing bowl, systematically combine the eggnog, heavy cream, vanilla extract, ground nutmeg, and a pinch of cinnamon. Whisk the concoction vigorously until it is evenly blended and slightly frothy, creating a velvety texture.
For a refreshingly chilled rendition, fill a cocktail shaker with a handful of ice cubes. Pour the eggnog mixture over the ice and secure the lid. Shake gently for about 30 seconds, allowing the mixture to cool down beautifully.
To add an extra decorative flair, take your serving glasses and drizzle the chocolate syrup around the inner walls, creating a visually appealing swirl.
Carefully pour the eggnog mixture into the prepared glasses, leaving a little room at the top to accommodate a luscious layer of whipped cream.
Generously top each glass with a dollop of whipped cream, and for an artistic finish, sprinkle a light dusting of cocoa powder on top.
Serve these delightful beverages immediately, inviting your guests to indulge and soak in the festive cheer!