Add the sugar, yeast and milk together and mix until the sugar has dissolved into the milk. Make sure that the milk is room temp.

Add the sourdough starter, flour and eggs to the bowl and mix into a rough dough. Allow it to sit for 15 minutes.Don't worry if the mix appears dry, it will soften up once you add the butter.

Now add the room temperature butter and salt and knead it into the dough until the dough is smooth and elastic.

Once the dough is smooth and pulling away from the sides of the bowl, set it aside to rise. You want the dough to double in size.

Once the dough has doubled, divide it into four equal pieces. The easiest way to do this is to weigh the dough and divide it by four - weighing will give you a better end result. I divided my dough into 4 equal portions of 270g.

Form each quarter of dough into a ball. Allow it to rest for 10 minutes before rolling each ball out into a disc. If the dough resists at any stage, just let it rest for 10 minutes so the gluten can relax.I found that it is easy to stretch the dough over a dinner plate to shape it. The dough is elastic and should not be sticky so this is possible.Each disc should be around 25 to 30cm across (10 - 11 inches).

Once you have four discs, lay out a sheet of parchment paper on a round pizza tray or flat cookie sheet and place one of the discs of dough in the middle.It's really important that the tray you use has no lip or it can cause the star to become misshapen.

Spread this with ⅓ of the nutella.

Lay the second disc on top and spread that with another ⅓ of nutella.

Now lay the third disc on top and spread it with the remaining nutella and place the forth disc on top.So you should have 4 layers of dough with 3 layers of nutella in between.

Allow the dough to rest for a few minutes and then roll it out slightly using a rolling pin to ensure that all of the filling is spread evenly and the dough is cohesive.

Now, place a small glass jar at the centre of the dough.

Using a knife, you want to make 16 cuts in the dough to form 16 pieces of dough to twist. To do this easily, use your knife to cut the dough into 4 even quarters, making sure that you only cut up to the jar edge. Now cut make a cut in the middle of each quarter and then a cut between each of those - making 16 cuts in total.I've put a full color pictorial in the blog post above.

Take two pieces of dough and twist them away from each other, joining the back together at the top. Repeat this 7 more times to create 8 twists of dough revealing the nutella and making a pretty star.

Allow the star to proof for around 30 minutes while you preheat the oven to 180C/356F.

Apply egg wash to the entire star using a pastry brush and bake at 180C/356F for around 25 - 30 minutes. The dough has a lot of butter, milk and sugar so you will need to keep an eye on it as it will burn easily (see cooking notes below as cooking time can vary depending on your oven).

The star is cooked when the dough is golden brown.

Take the star out of the oven and allow it to cool slightly before dusting with icing sugar. Best eaten warm!