Searching for plum cake recipe

When my mom was growing up, her mom made a plum cake. The best she can remember is plums were layed on top of the batter. It was baked and then a topping was put on it and put back in the oven. My grandmother was German, if that will be of any help. Mom’s 88 years old…would love to surprise her for Mother’s Day.
Thanks.

Kitchen Witch
Thank you so much. Just in time for Mother’s Day to try
one of these.
Caole