Warm the flour slightly. Make a well in the center and place salt and sugar around the edge. Crumble the yeast into the center and add some lukewarm water. Let rest covered in a warm place for about 15 minutes.
Add butter to the lukewarm milk and let it melt, then stir in the egg yolks. Let rest again. Once the yeast starts to bubble, add the remaining ingredients and beat well (preferably by hand until bubbles form in the dough). Add raisins if desired.
Let the dough rise again for about 45 minutes in a warm place. Shape about 50 balls, flatten them and stretch gently with your fingers so the edges are thicker and the center thinner. Fry immediately in hot oil until golden brown on both sides. Drain on kitchen paper and serve warm.