Can’t eggs be used for a Bavarian cream filling?
It depends on what you’re using the filling for, reader Gerri. A cream-filled doughnut? Sure, an egg-thickened filling will work just fine. However for a big item like a Charlotte, where the gel needs to support the structure, there’s nothing like gelatin. To have any structural strength, an egg custard needs to be gently cooked all at once. Think of a flan. You pour the filling into the mold and heat it until the eggs set. The problem is that the larger the mold gets, the longer it takes for heat to penetrate all the way through. By the time the center sets, the outside is usually over-cooked. This is why large flans generally have that scrambled egg look on the outside.
But even if they don’t overcook, flans are very eggy tasting. That’s because it takes lots off eggs to hold the flan up. That taste can be a good thing for, say, a flan. However for a fruit mousse (fruit Bavarian), where you really want to taste fruit (and maybe cream), gelatin provides not only strength and silkiness, but also a neutral flavor. It also sets up without the need to apply heat.