Put the plain flour, fast action yeast, salt and sugar in a large bowl. Make sure that the salt and the yeast do not directly touch each other. Stir together
In a pan on a low heat, warm up the milk and butter until the butter melts, then add the vanilla extract. Let the mixture cool for 5 minutes or until lukewarm, then whisk the egg into it
Pour the milk mixture into the flour mixture and bring everything together into a sticky dough
Knead the dough for 10 minutes either by hand on a floured surface or in a mixer with the dough hook attachment
Place the kneaded dough in a oiled bowl covered with cling film and leave in a warm place to rise for 1 hour or until doubled in size
Roll out the risen dough into a rectangle measuring roughly 40 x 30cm (16 x 12").
Spread the Nutella over it, then cut the raspberries in half and add them on top of the Nutella
Roll the dough into a sausage shape from the longest side, used a sharp knife to trim the ends then cut it into equal pieces. You can mark out the pieces before you cut with a ruler, you want them about 1 inch thick
Place the cut rolls into a lined traybake tin (I used a 12" x 9" one), cover them loosely with cling film and a tea towel and leave them to rise for 1 hour
Pre-heat your oven to 180C Fan/200C/350F/Gas Mark 4
Bake the rolls for 20-25 minutes, until golden brown
Drizzle with warm Nutella and sprinkle over the freeze dried raspberries if using
Serve immediately, store leftovers in an airtight container for up to 2 days. The buns can be frozen without the decoration