Whats the difference between bavarian and boston cream dounuts?

Ok I know the answer to this. I've worked at Dunks for like 5 years. They only diffrence is that Boston Cream has chocolate on top, and bavarian has powder on it. They has the same cream in the middle.Whats the difference between bavarian and boston cream dounuts?
Some places used the same cream for both, but traditionally, a bavarian donut, was made with bavarian cream. . . Which is like a whipped cream, only lighter, generally made with a non dairy substitute. It has powdered sugar on the outside. A boston cream donut is, of course, a knock of on Boston Cream Pie, which is gold cake, chocolate frosting and custard. So, the donut has custard instead, and a chocolate topped frosting. Both are delicious! LOL