Preheat the oven to 425 degrees F.

In a large bowl, combine the yolks and sugar and whisk well until the mixture is pale and fluffy.

In a separate bowl, combine the semolina flour, tipo 00 flour, lemon zest, baking powder and salt and mix well. Stir in the butter and mix well, then fold in the egg yolk mixture and mix well. Fold in the raisins and continue to mix to form a homogenous dough. Roll the dough out to 1/4 inch thick and cut it into 2-inch lozenge or parallelogram shapes. Butter a cookie sheet and place the lozenges on the sheet. Bake for 12 minutes, or until golden brown and firm. Serve hot or at room temperature.