Bread: Combine the yeast, sugar and water in a small bowl then whisk until the yeast is dissolved. Cover and leave for 10 minutes or until it becomes frothy.
Sift the flour and salt into a large bowl then stir in the milk, butter and yeast mixture. Combine into a soft dough.
Turn the dough onto a floured surface and knead until smooth and elastic; about 5 minutes. Place dough into an oiled bowl, cover and leave in a warm place about an hour or until it has almost doubled in size.
Filling: In a fresh bowl combine the butter, Nutella, sugar and cinnamon.
Turn out the dough onto a floured surface then shape into a rectangle about 20 x 26 centimetres. Spread with the Nutella mixture then roll up to create the swirl in the bread.
Place the roll in a 14cm x 21cm loaf tin then cover with plastic wrap and stand in a warm place for about 40 minutes or until the dough has almost doubled in size.
Remove the plastic and bake in a preheated oven at 220 degrees C for 20 minutes then drop the temperature to 160 degrees C and cook for a further 25 minutes.