Roll out your dough on a floured surface to about 1.5 feet in size. Melt your butter and spread it over the whole dough - do not leave any areas without butter. Next, sprinkle the cinnamon sugar mixture throughout. Lastly, spread your blackcurrant jam over the whole surface of the dough.
Fold the long side of your rectangle opposite from you, towards yourself, lengthwise, to the middle of the dough. Now take the long side closest to you and fold over all the way to the end of the other long side.Carefully use your rolling pin to flatten this 3 layer dough a bit and spread it out. Some of the jam may start to come out, but that is okay, stick it back together and try as best you can to get the largest rectangle you can. It will be about 1.5 ft in length, but now only about 6-8 inches in width.
Prepare a parchment paper lined baking sheet. Slice the dough into 1- 1.5 inch strips along the long side. This will give you 14 strips. If you want smaller rolls, just cut thinner strips. Take one strip and hold on either end to twist. You should get a pretty pattern with the purplish jam. Then twist together into a knot and place on your baking sheet. Repeat for all knots. Cover with plastic wrap and let rise another 15-20 minutes.
Preheat oven to 375F. Mix the egg and water together and brush over all exposed areas of knots. Sprinkle with turbinado sugar. Bake for 16 minutes total, turning pans in oven at 8 minutes for even baking. Remove and let cool on cooling rack for 15-20 minutes. Enjoy!