In a bowl of a stand mixer fitted with a paddle attachment, combine the granulated sugar, warm milk and active yeast. Let it stand for 10 minutes or until mixture is foamy.
With the stand mixer on low, add in the one cup of flour, mixing only until it is combined. Next, pour in the melted butter and blend until combined. Beat in 2 eggs. Gradually add salt and the remaining flour and beat until a soft dough forms (5-10 minutes).
Loosely cover the bowl and place in a warm, draft free place for 1 hour (until it has doubled in size).
Line a baking sheet with parchment paper or non stick spray.
On a lightly floured surface, punch down dough and turn out. Gently, shape into a ball. Cover loosely and let rest for an additional 10 minutes.
Roll out dough into a 12x15 rectangle. Spread Nutella in an even layer on the entire surface, leaving about a ½ inch border of dough. Roll the dough tightly and place on the parchment lined baking sheet that has been sprinkled with flour.
Cut the dough down the middle with a knife, leaving one end intact. Twist the ends over the top of each other, making sure cut side is towards the top. Cover braid loosely with plastic wrap and let it rest for 20 minutes.
Preheat oven to 350°. Brush the surface for the dough with the egg wash. Bake for 20-25 minutes. Increase temperature of the oven to 425° and bake for about 5-7 more minutes. Remove from oven and cool before serving!