Warm the milk in a small saucepan until it bubbles, then remove from heat and let cool until lukewarm. In a large bowl, dissolve yeast in lukewarm, scalded milk. Add 250g flour. Stir well and allow to rest 1 hour in a warm place.
Soften chopped raisins in warm water for 30 minutes.
Beat egg, egg yolks, sugar, vanilla, melted butter, salt and orange zest. Add to yeast mixture. Stir in raisins. Stir in egg mixture. Blend well. Add 500g flour. Mix well, forming smooth ball. Dough will be somewhat soft, but not "batter-like." Cover dough and allow to rise until fully doubled. Punch down, let rise until double again.
Roll dough into 1.25cm balls, set aside to rise until doubled in bulk. In a deep fat fryer, heat oil to 190 degrees C.
Drop 2 or 3 at a time into hot fat, turn when deep golden brown. If removed too soon, dough will be uncooked inside. When done drain briefly and dust with icing sugar before serving.
Compressed fresh yeast can be purchased at bakeries that make their own breads from scratch. If this is unavailable, use a 7g sachet of dried active yeast.