Place filling ingredients (not including optional filling ingredients) into TM bowl and mix 5 sec/speed 5. Set aside but do not clean bowl.
To make Dough: Place milk and butter into TM bowl and heat 3 min/50ºC/speed 1.
Add yeast to TM bowl, then other dough ingredients with the egg added last.
Mix 6 sec/speed 6, then knead 2 min/Interval**.
Lightly oil a Silpat mat to the edges, tip the dough out onto the mat, wrap to enclose dough and allow to rest for 40 minutes.
Whilst dough is proving, grease the sides of a 24cm round cake tin, and line base with baking paper.
Once dough is proved, unwrap it and using your hands (dust with flour first) press your fingers onto dough to stretch it out to 35cm x 25cm, with the widest edge facing you.
Spread filling evenly onto dough with the back of a spoon, starting from the middle and working outwards, and if using fruit and nut scatter that over filling.
Using a dusting of flour as you go (to prevent sticking), roll dough into a cylinder by lifting the widest edge of the mat away from you, and gently working the dough away from the mat so that it ends up looking like a large Swiss roll. Finish with the roll sitting on its seam line.
Before cutting dough into 7 pieces (one smaller than the other 6), roughly determine where you wish to cut the log and lightly mark the spots with a small knife.
Slide the dental floss underneath each section where you need to cut, and holding an end of dental floss in each hand, cross your hands over the top of the log pulling the dental floss through the dough as you go. As you cut each bun, place them into the cake tin starting with the smallest bun in the middle first, then work your way around.
Allow to rise in a warm place until doubled in size (approx 30 to 45 minute). Meanwhile, preheat oven to 180ºC fan forced, and place a shelf in the middle.
Glaze risen buns with beaten egg and dust with caster sugar before placing cake tin onto a baking tray and into the oven. Bake for 25-30 minutes until golden brown.
Allow buns to cool for 10 minutes before releasing from cake tin and cooling on a wire rack.