How to Make It
Pulse the almonds in a food processor until finely ground. Add the flour, sugar, baking powder, salt, and nutmeg and pulse to combine. Add the butter and pulse until the mixture resembles coarse crumbs. Add the egg yolks and vanilla and pulse until the dough holds together when squeezed.
Transfer a quarter of the dough (about 1 cup) to a sheet of plastic wrap and press into a disk; refrigerate until firm, at least 1 hour and up to 2 days. Press the remaining dough into a 9-inch tart pan; refrigerate until firm, at least 1 hour and up to 2 days.
Heat oven to 350° F. Roll the disk of dough to a thickness of ¼ inch on a well-floured surface. Cut the dough into rounds. Spread the jam over the dough in the pan. Top with the rounds of dough. Bake until the crust is golden brown, 35 to 40 minutes.