Humm ... very curious problem sheff. I, too, am stumped as to what a raw egg flavor is.
Aside from some flavoring from the chicken feed, about the only two flavors in raw eggs that you "might" be tasting would be either the natural iron or sulfur, or maybe a combination. The first things that pop to my mind are:
1) Do you notice this problem with other cooked egg dishes?
2) Do you notice this problem with cakes purchased from a commercial bakery?
3) How fresh are the eggs (from the store)?
If you don't taste a "raw egg" flavor from commercialy baked goods - one solution might be to substitute powdered eggs (gag- what an awful taste they have to me) or try freezing the eggs for a minimum of 72-hours before thawing and using.
"It ain't what you don't know that gets you in trouble. It's what you know for sure that just ain't so." - Mark Twain