Which cocktail contains an egg yolk as an ingredient?

The cocktail that contains an egg yolk as an ingredient is the Golden Fizz. This cocktail is part of the fizz family and is traditionally made with fresh ingredients that include a whole egg or just the yolk, which contributes to its creamy texture and rich flavor. The inclusion of egg yolk in the Golden Fizz provides a unique mouthfeel and adds richness to the drink, making it a luxurious choice for a cocktail enthusiast.

Other cocktails mentioned do not typically include egg yolk in their recipes. For instance, the Grasshopper is known for its mint and chocolate flavors, the Godfather is a simple mix of whiskey and amaretto, and the Greyhound is a refreshing blend of vodka and grapefruit juice. None of these incorporate egg yolk as part of their standard formulation, highlighting the unique nature of the Golden Fizz.