01 - In a bowl, combine the lukewarm milk and yeast. Let it sit for about 10 minutes until frothy.
02 - In a large mixing bowl, combine the flour, sugar, and salt. Make a well in the center and add the yeast mixture, melted butter, and eggs. Mix until a dough forms.
03 - Knead the dough on a floured surface for about 10 minutes until smooth and elastic. Place in a greased bowl, cover, and let it rise in a warm place for about 1 hour or until doubled in size.
04 - In a pot, combine the ground poppy seeds, sugar, milk, honey, and vanilla extract. Cook over low heat for about 5 minutes, stirring until combined. Remove from heat and let it cool. Stir in raisins and walnuts if using.
05 - Preheat the oven to 180°C (350°F).
06 - Once the dough has risen, roll it out on a floured surface into a rectangle (about 1 cm thick). Spread the poppy seed filling evenly over the dough.
07 - Roll the dough tightly from one long side to the other, pinching the edges to seal. Place the roll seam-side down on a baking sheet lined with parchment paper.
08 - Let the roll rise for another 30 minutes.
09 - Bake in the preheated oven for 30-45 minutes or until golden brown.
10 - Allow to cool before slicing.