Measure the flour into a big bowl and make a well in it. Measure the yeast and the sugar into the well and add the water. Flick some flour over the well to close it and let it sit for 1 hour.
Add the salt and the butter and knead for 10 minutes by hand or by machine. If you are using a machine, put it on the lowest setting.
Cover the dough and let it sit for 1-2 hours until it has doubled in size. You can also let it rise in the fridge overnight.
While it is rising, beat together the butter, sugar, and cinnamon for the filling and set it aside.
Also prepare the goo by melting the butter and the sugar together and scraping it it into the pan in which you will bake the buns. Swirl it all around so it evenly coats the bottom of the tray and set it aside.
When the dough has risen, pull it out onto a lightly floured surface and, using a rolling pin, roll it into a rectangle about 12x9 inches (the size of an A4/letter piece of paper).
Patiently spread the filling all over the dough. A scraper is a good tool for this. Take your time, this is not as easy as it sounds. If you are using crushed pecans (or walnuts) scatter them over the surface of the dough.
Roll up the dough from the long side into a tight sausage and cover it with a tea towel. Slice it into 12 equal slices. This can be easier if the dough is cold. If your dough is warm you can pop it in the fridge for 30 minutes or so to let it cool down.
Snuggle the slices into a baking tray. When they are all in there, turn them all over (seriously) as that way the tops and the bottoms are all buttery. You do not want to roll them in melted butter before putting them in the tin. They absorb too much butter that way. Seriously, the melted and cooled butter / sugar mixture with this method is the perfect combo for this particular job. Cover the tin with a tea towel and let them rise for 45 minutes.
Preheat the oven to 200 degrees C (400 degrees F) and pop the buns in. Check them after 20-30 minutes and cover them with baking parchment to make sure the tops do not get too brown. Bake them for 45 minutes in total.
When they are done, remove them and carefully invert them on to a big plate. Be CAREFUL. Don't burn yourself with hot goo and don't lose any!
Let them cool before you eat them or you will burn yourself on boiling hot syrup. You have been warned!