Whisk together the lukewarm milk, sugar and must, sprinkle the yeast on top, cover and let sit for 30 minutes.
Add the flour, sugar, egg yolk, vegetable oil and a pinch of salt. Start to knead and add the must mixture a little at a time until just combined. Cover the bowl and let rest.
Knead the dough again and in the last minute add the raisins, knead to combine. Cover the bowl and let rise for 2 hours or until doubled.
Form into a smooth ball. With the handle of a wooden spoon, poke holes through the dough. With your fingers, stretch the hole bigger. Place them on the prepared cookie sheet. Brush with a little milk, cover and let rise until doubled.
Bake in a pre-heated oven until golden.