Special cake with plums 300g

What Grandma says: Once, I would catch my husband, grandpa, eating plum marmalade on a bread slice at any time of day or night, if I forgot to put the jar back into the closet. So I thought I could surprise him a little and invent for him some dough that goes perfectly with the plum marmalade: neither too soft, lest it should absorb all the filling, but not too hard either, lest the marmalade should spread at every bite. I was greatly successful with my cake and I remember that, long afterwards, he would keep calling me “my beloved specialty.”