Combine the flour, salt, sugar and instant yeast in a bowl of a stand mixer. Make a well in the center. Add in all wet ingredients: milk, egg and tangzhong. Fit the dough hook attachment on your stand mixer and begin mixing on medium speed and knead until your dough comes together and then add in the butter and continue kneading. Keep kneading until the dough is smooth, not too sticky on the surface and elastic. I kneaded the dough for about 18-20 minutes. Each mixer may vary.

When the dough is ready, you should be able to take a chunk of dough and stretch it to a very thin membrane before it breaks. When it does break, the break should be form a circle.

Knead the dough into a ball shape. Take a large bowl and grease with oil. Place dough into greased bowl and cover with a wet towel. Let it proof until it’s doubled in size, about 40 minutes.

Transfer to a clean surface. Divide the dough into two equal portions. Knead into balls. Cover with cling wrap, let rest for 15 minutes.

Roll out each portion of the dough with a rolling pin into a thin rectangle.

Spread nutella across rectangle, leaving about one inch of dough along the edges. Roll up dough from the short end. Place in loaf pans and cover with plastic wrap. Let them rise until double the size, approximately another 40 minutes. The dough should fit across most of the loaf pan when it is finished rising.

Beat an egg and brush egg mixture on top to create shiny eggwash finish.