Pour boiling water from a kettle over the poppy seeds. Add to a saucepan and cook in 500ml milk till poppy seeds are soft and the milk is absorbed. (If the poppy seeds are soft but there's still a lot of milk left in the pan, drain most of the milk from the pan.) Cover and leave overnight.
The next day, pass the poppy seed mixture through a meat grinder twice.
Pour boiling water over the nuts and raisins. Drain and chop.
Beat together the butter and sugar. Beat in 5 egg yolks, then gradually stir in the poppy seeds, nuts and raisins, and almond extract.
Beat 10 egg whites till stiff peaks form. Gently fold into the poppy seed mixture.
Combine 2 tablespoons sugar and fresh yeast and leave in a warm place till foamy.
In a large bowl, combine the flour and vanilla sugar. When the yeast mixture is foamy, add to the flour along with the 5 remaining egg yolks and 350ml of milk. Mix well. Knead into a soft and smooth dough, adding a bit more milk if necessary in case the mixture is too dry.
Preheat the oven to 180 C / Gas 4.
Roll the dough into a long log and divide into 6 equal pieces. Roll a piece out to a rectangle about 5mm thick. Spread some of the poppy seed mixture over the dough, leaving space at the edges. Roll up, swiss roll style, then wrap tightly in baking parchment, rolling up the ends. Place the parcel on a baking tray or roasting tin. Repeat with the remaining 5 pieces of dough.
Bake in a preheated 180 C / Gas 4 oven for 45 minutes. Remove from the oven and allow to cool slightly, then unwrap.
Once cooled completely, you can cover the rolls with a simple icing or glaze and flaked almonds.