Dice toast. Heat milk and pour over bread cubes. Let it soak for 20-30 minutes. Finely chop the walnuts.Separate the eggs and beat the egg whites until stiff. Cream the butter while gradually adding sugar, vanilla sugar, egg yolks and lemon zest. Stir in soggy bread, walnuts and breadcrumbs. Fold in beaten egg whites and cranberries. Grease a bundt cake form (approx. 4 1/4 cup or a pudding dish with lid) with butter and coat with breadcrumbs. Pour in breadmixture. Cover bundt cake form tightly with aluminum foil. Fill a large pot with 6 inches of water and bring to a boil. Immerse bundt cake form into the water. Cover pot with a lid and let it simmer for about 45minutes over low heat. Boil cranberry juice. Whisk cornstarch with some cold water. Stir juice with cornstarch and bring to a boil again. Add cranberries and let it cool. Remove bundt cake form from the water.