There is a batter of sorts that goes into a Tom and Jerry, definitely. A lot of stores here in the upper Midwest even sell the premade batter this time of year. As a former English instructor, I shudder to mention Wikipedia here, but they've got the quick, simplified description of the drink: "Preparation: Separate Eggs, Beat Egg Whites until stiff. Mix Egg Yolks with Powdered Sugar, Put spoonful of yolk mixture in cup, mix with brandy and rum, Fold in some Egg White then add hot milk and top with more Egg White, stir gently to fold in the egg white. Top with Nutmeg." And yes, the chaotic capitalization is all Wikipedia.
I'm with you on the Creamy Brandy Alexander; I'm definitely intrigued by that one.