Heat milk for 35-40 seconds in the microwave or until warm (100 degrees)

In a small bowl, stir together yeast, 1 teaspoon sugar, 1 tablespoon warm milk.

Let the yeast mixture sit for 4-5 minutes or until the mixture becomes foamy.

Using a stand mixer with the dough hook attachment, place flour, butter, eggs, salt, remaining milk and sugar, and yeast mixture into the mixer bowl.

With speed on medium, knead dough until a ball forms. Add additional flour, 1 tablespoon at a time, if needed.

Once the dough ball is formed, transfer to a lightly oiled mixing bowl, cover with a clean kitchen towel, and let rise in a warm place for about 1 hour or until the dough has doubled in size.

Once dough has risen, transfer onto a floured surface and shape into a rectangle.

Using a rolling pin, roll dough out into a large rectangle, about ¼ inch thick.

Spread Nutella over dough, covering completely.

Sprinkle walnuts evenly on top of Nutella.

Roll dough into a log shape and pinch together the end to create a seam and seal the dough log.

Slice into 8-10 rolls using a very sharp knife or thread.

Place rolls into a greased 9x13 baking dish and cover with kitchen towel. Set in a warm place until doubled in size, about 30-40 minutes.

Heat oven to 350 degrees.

Once rolls have risen, bake for 24-26 minutes or until golden brown.

In a small bowl, whisk together powdered sugar, milk, and vanilla until smooth and clumps are gone.

Drizzle icing over rolls immediately after removing them from the oven.