I can remember my grandmother cranking the handle of a silvery grinder bolted to the edge of the kitchen table. Tiny grayish-black seeds filled the hopper, slipping and sliding down to the augur, where they turned into the black sandlike paste emerging from the holes of the disk. Anyu blended the ground seeds with sugar, lemon rind, and golden raisins, with milk to moisten. And I anticipated the kalács that would hold mákos,this black gold: bread-like yeast dough spread with a thick layer of poppyseed filling and then rolled and baked until golden. How we would fight over the slices at our holiday meals! Those with quick reflexes would be rewarded with slices containing the most generous servings of poppy filling; dawdlers were stuck with the doughy heels of the loaf.
Poppy seeds are a common ingredient in Eastern European baked goods. I used to rely on canned poppyseed filling, but learned that it's so much tastier made fresh. This filling is appropriate for Kolache cookies, Hamentaschen, Danish, and Anyu's Kalacs. I'm using mine for a poppyseed version of Ottolenghi's Kranz Cake (or what us New Yorkers call Babka).
Thanks to Hepzibah at allrecipes.com for the inspiration. —Windischgirl
Using a spice or coffee grinder, or a blender, grind the poppy seeds to a sand-like texture. Break up any lumps that form. Set aside.
In a 2-quart saucepan over medium-low heat, heat the milk, sugar, margarine, and lemon zest. Stir until the sugar dissolves. The milk should be steaming but not simmering.
Break the two eggs into a medium bowl (I used a 2-cup measuring cup) and whisk until blended. Continue to whisk while slowly pouring in about half of the milk mixture, in order to temper the eggs. Pour the egg-milk mixture back into the pot, whisking constantly, until the mixture thickens; it is thick enough if it coats the back of a spoon.
Turn off the heat. Gradually whisk in the ground poppyseed until it is moistened. Whisk in the vanilla and lemon juice to taste. If using the raisins, then can be added now, while the mixture is cooling.
Store the filling in a tightly-sealed container in the refrigerator for up to 5 days. And no fighting!