I was surprised to learn that there is an easier — and better — way to get an almond essence in a plum-based pastry. The flavor is already there, in the plum kernel. Inside the pit is a small almond-shaped nut, perhaps a quarter the size of an almond: the taste is more like marzipan. The kernel is actually the seed, with the pit serving as a protective coating.
My father is responsible for telling me about this: it seems his mother assigned him the task of cracking the pits for their kernels so she could use them in jam herself. I’ll follow her lead.
NB: as readers of Sherlock Holmes may recall, cyanide or prussic acid is known by the telltale smell of almonds. Plum kernels contain trace amounts of prussic acid, but in inconsequentially tiny amounts. And you’ve probably been taking it in without realizing it, since “Cherry seeds, peach and plum pits, corn, chickpeas, cashews, and some other fruits and vegetables contain cyanogenic (i.e., cyanide-forming) glycosides. . . . ”
So it’s not as risky as fugu . .