In a bowl, dissolve yeast in ¼ cup of water and let sit for around 10 minutes. Combine flour, salt, and sugar in a mixer bowl. Add yeast and the rest of the water, then mix on low and medium. You will have to knead dough for a few minutes after. Place dough in a lightly oiled bowl, cover it and let it double in size. This process takes about an hour. When your dough is ready, sprinkle flour on a surface and roll it to form a rectangle. Spread Nutella in an even layer on the surface, leaving a small border of dough. Roll tightly and place on a baking sheet that you have previously sprinkled with cornmeal. Cut the dough down the middle with a knife, leaving one end attached. Twist ends over top each other, making sure the cut side is toward the top. Cover dough loosely and let sit for 20 minutes. Brush the surface on your bread with egg-wash and bake for around 20 minutes in a preheated oven (350 F). Raise temperature and bake until lightly browned on top, about 5-7 minutes more. Let cool before serving (we recommend vanilla ice cream to go). Bon Appetit!