I mean, do the ingredients differ in some way, other than maybe how much cocoa powder you put in? Yesterday I was looking for a caramel cake mix – I swear there used to be some, but none to be found – while all the major brands had CHOCOLATE and DOUBLE CHOCOLATE (I think added pudding mix was the the key?) and TRIPLE CHOCOLATE (same as double but plus chocolate chips?) and DEVIL’S FOOD … but I have no idea what makes that different.
Oh, and GERMAN CHOCOLATE, but that is definitely less chocolate and lighter in color, plus the special frosting generally.
A devils food cake uses more baking soda, and oil instead of butter. Also water instead of milk or heavy cream. Devils food cake is the only cake I use an egg white frosting on as well, not sure if that is traditional or not.
You make a syrup from 2 parts sugar and 1 part water and stir it into a meringue mix where it cooks the egg whites, delicious frosting but only good for a couple of days before the texture starts to change. Very easy t make and well worth the trouble. Egg whites, sugar, water and vanilla, I use a little corn syrup in mine.
it’s not ideal for a full-sized cake since it’s quite sticky. I find it works wonderfully for cupcakes.
It is a bit like meringue, in terms of ingredients. It’s VERY different from a meringue buttercream (which also involves egg whites, but the addition of butter); there are several types including Swiss and Italian. Comparing Types of Buttercream Frosting - Baker Bettie
By that definition, this recipe (hopefully link works, as it’s a NY Times recipe) would qualify as devil’s food, not chocolate: Chocolate Olive Oil Cake Recipe - NYT Cooking (nytimes.com)
I haven’t made this one, but I have made a different olive-oil-based cake in the past (again, for the relative with food allergies).