Traditional Linzer dough is often made with finely ground almonds, sieved hard-boiled egg yolks, lemon zest, spices, and raspberry jam. Using pre-cooked egg yolks lends extra richness to the dough but does not act as a binder. Use either seeded or seedless jam, I prefer seedless in cookies. I think it is also fun to use other jam flavors such as apricot, blackberry, or marionberry. I made this batch using raspberry jam for half the cookies and apricot jam for the other half.