Prepare the Poppy Seed Filling:
Rinse the poppy seeds under hot water in a fine sieve to remove any bitterness. In a pot, cover the poppy seeds with the milk, bring to a boil, then simmer on low heat for 20–30 minutes until the seeds are soft. Drain very well, pressing out all liquid, then grind the poppy seeds twice using a poppy seed grinder, meat grinder, or high-powered blender/food processor.
Make the Poppy Seed Mixture:
In a pan, combine the ground poppy seeds, sugar, honey, butter, raisins, nuts, vanilla extract, and orange zest. Heat gently while stirring until thickened and well combined. Allow the mixture to cool completely. Once cooled, gently fold in stiffly beaten egg whites (optional) to make the filling firmer.
Prepare the Dough:
In a small bowl, combine the warm milk, yeast, 1 tablespoon of sugar, and 2 tablespoons of flour. Let it sit for 10 minutes until foamy. In a large bowl or stand mixer, combine the remaining flour, sugar, salt, and lemon zest. Add the eggs, melted butter, and yeast mixture. Knead the dough for 8–10 minutes until smooth and elastic. Place the dough in a greased bowl, cover it, and let it rise in a warm place for 1–1½ hours or until doubled in size.
Assemble the Roll:
Preheat the oven to 180°C (350°F). Line a large baking sheet with parchment paper. On a lightly floured surface, roll the dough into a large rectangle, approximately 40×50 cm and 4–5 mm thick. Spread the cooled poppy seed filling evenly over the dough, leaving a small border around the edges.
Roll and Shape:
Starting from one long edge, carefully roll the dough up tightly into a log shape. Seal the edges by pinching them together. Place the rolled dough seam-side down on the prepared baking sheet. If desired, shape the roll into a spiral or coil for an extra decorative touch.
Bake the Roll:
Bake the poppy seed roll in the preheated oven for 25–30 minutes, or until the roll is golden brown and cooked through. Allow it to cool slightly on a wire rack.
Prepare the Glaze:
In a small bowl, whisk together the powdered sugar, lemon juice (or water), and almond extract (if using). Drizzle the glaze over the cooled poppy seed roll.
Decorate and Serve:
Sprinkle the top of the roll with chopped walnuts and poppy seeds (if desired). Let the glaze set for a few minutes before slicing the roll into servings.
