This looks like a filling for a cake. I have to say that these days I’m not a big fan of uncooked eggs. I do wonder if pouring the boiled sugar water into the beaten egg would serve to cook it.
Lady Baltimore Filling
Boil 1 1/2 c sugar with 1 c water for 10 minutes. Beat white of 1 egg to stiff froth. Pour syrup on egg white, beating steadily until a meringue is formed that will spread. 1/2 teas vanilla. Add 1 c raisins & 1 c nuts.
I’m not sure I want raisins and nuts in a meringue filling. I also don’t think the syrup would do enough to cook the egg whites to ease your mind about the raw egg issue. I think a standard 2-layer cake wouldn’t take to this filling very well. It seems to me the top layer would have a tendency to slide off. I think it would be better in a chiffon cake where you bake it in a tube pan, cut about an inch off the bottom and then hollow out a filling cavity. I’ve done that with mousse fillings and they’re yummy–like a really fancy version of the old Bundt Tunnel-O-Fudge cakes.
I actually just did a quickie search for Lady Baltimore cake and it really is/was a layer cake with this filling and a lovely meringue “frosting” that covers it all, rather like a baked Alaska.