Chocolate Nutella Strudel

Name: Chocolate Nutella Strudel
Prep time: 40 min
Cook time: 40 min
Total time: 1 h 20 min
Cuisine: European, German
Ingredients: 1 tablespoon instant yeast (or baker's yeast); 1 tablespoon sugar; 1.3 cups milk; 3 tablespoons butter; 4 tablespoons warm water; 3.5 cups flour; 2 ounces dark chocolate (or baking chocolate, grated); 1/2 teaspoon salt; 2 tablespoons sugar; 1 egg yolk; 8-9 ounces Nutella