01 -
Mix together the flour, sugar, and yeast in a big bowl. Toss in the lukewarm milk, eggs, vanilla, and salt. Stir until combined, then knead slowly while adding the soft butter bit by bit. Keep at it until the dough feels smooth and stretchy—this should take about 10 minutes.
02 -
Put the dough somewhere warm and cover it. Leave it alone for around 1 to 1.5 hours or until it puffs up and doubles in size.
03 -
Roll the dough out into a huge rectangle on a floured surface. Evenly spread Nutella over it, making sure to leave a small border around the edges. Sprinkle hazelnuts over the Nutella if you're using them.
04 -
Starting at the longer side, carefully roll the dough into a log. Slice the rolled dough into 12 even pieces.
05 -
Place the slices, cut-side up, into a greased baking pan. Let them rest for 30 minutes under a loose cover.
06 -
Set your oven to 175°C (350°F). Bake the buns for 25-30 minutes or until they turn golden on top.
07 -
Mix the milk with the powdered sugar until smooth. Pour it over the warm buns right before eating.