Soak the raisins in warm water to soften.
Dissolve the yeast in the warm milk and slowly add two tablespoons of flour using a whisk to avoid forming lumps. When the mixture is smooth, cover with a cloth and leave it to rise until it doubles in size. In another bowl put the remaining flour, the yeast mixture, a whole egg plus 3 yolks, mix well and add the sugar, the fat (at room temperature) and a pinch of salt. Mix again and add the remaining ingredients: pine nuts, the raisins (drained and squeezed), the grappa. Mix all the ingredients and leave to rise. Covered with a cloth, for about an hour.
Heat the oil to 170° C. As soon as it is ready, use a soup spoon to take a good quantity of the mixture and add it to the hot oil, letting it fry until golden. Drain the croquettes on a plate covered with paper towel.
Dust the croquettes with icing sugar and serve.