Knead a dough from the flour, 2 eggs and apinch of salt. If eggs are large, you may have to add alittle additional flour.
Stretch the dough into a thin sheet and let it rest for 15 minutes. Cut it into strips about ¼inch wide, like egg noodles.
Bring to a boil the milk, vanilla bean, apinch of salt and 1tablespoon butter. Reduce heat and put in the egg noodles. Cook until the noodles absorb all the liquid, stirring often. This should take 10 to 12 minutes.
Mix in the raisins, remaining butter, the lemon rind, ¼cup of the sugar and the yolks of remaining 3 eggs. Mix well. Preheat oven to 375°F.
In a separate pot cook the cored and peeled apple halves in 1cup water and 2tablespoons sugar until they are half cooked. Remove apples and pat them dry.
Sprinkle the bread crumbs in a well-buttered baking-serving casserole of porcelain or heatproof glass.
Put threequarters of the noodle mixture in the casserole and pat down evenly. Place the half-cooked apples with cavities upwards in 2 even rows. Fill cavities with ground walnuts. Cover with remaining noodle mixture.
Bake the noodles in the preheated oven for 20 minutes.
Meantime, whip the egg whites with the last 2tablespoons sugar and the lemon juice to make a meringue.
Pour the meringue on the partly baked noodle casserole and bake for 15 minutes longer, till the meringue is golden brown.