Preheat oven to 350°F. Mix together all purpose flour, hard wheat flour, powdered milk, salt, sugar and instant yeast. Blend well. Set aside.
In a bowl, blend eggs, water and milk. Add to dry ingredients and continue mixing until all dry ingredients are hydrated. Add Dari Creme and continue kneading until smooth and elastic. Cut dough into 30 grams each. Round each dough and set aside.
Combine milk, sugar, egg yolks and cornstarch in a saucepan. Mix well. Cook over medium heat and continue stirring to prevent from forming lumps. When filling starts to thicken, add vanilla and margarine. Continue to stir until very thick. Set aside to cool.
Fill each dough with prepared filling and place onto baking sheet. Proof for 1 hour or until double in size. Meanwhile, preheat oven to 350°F. Brush with egg wash and bake for 20 minutes.