Preheat the oven to 180C/356F.
Whisk together the wet ingredients for the binder in a medium sized mixing bowl. Sprinkle over the psyllium husk powder, then whisk vigorously until it is fully incorporated and no clumps remain. Set aside for 10-15 minutes to form a gel.
Next, make the scald by whisking the flour and boiling water together. They should form a paste like consistency quite quickly. Set aside to cool a little.
Combine the ingredients for the dough in the bowl of your stand mixer. Use the paddle attachment to combine everything on a medium speed for 1-2 minutes or until the scald has ‘dissolved’ into the flour.
Add the binder, turn the mixer up and beat until completely combined into a smooth dough. There should be no flour left on the bottom of the bowl. The dough might be too wet to handle. If it is, place the bowl into the fridge for 15 minutes to firm up. The psyllium husk should work magic in that time.
Before we roll out the dough, we need our filling ready to go. Combine the cinnamon and sugar in a medium bowl. We’ll use the milk later to adhere the sugar to the dough.
Flour a large piece of baking paper, roughly 40 cm long, with tapioca flour or a light starch. Place the scroll dough on the paper and flour any sticky parts, then roll the dough out into a long, thin rectangle about the size of the baking paper.
The size of the rectangle isn’t super important, though. The longer and wider you roll it, the more ‘rings’ your scroll will have. Make sure the dough is reasonably thin (roughly ½–1 cm) but without any holes.
Splash a very small of milk onto the surface of the dough, just to moisten it. Evenly sprinkle the cinnamon sugar across the dough.
Beginning on the long side, use your fingers to fold the 1cm border of the dough up onto itself. You want to create a tight roll, so try and make this first notch as small as possible. For large scrolls, start the rolling on the short side of the dough. Continue folding the dough up until you can begin to use the baking paper to roll the dough onto itself. Take it about 80% of the way, then take the far side of the dough and bring it up over the log. You should have a log of dough with the seam facing upwards.
Line your baking dish with baking paper or grease it with vegan butter. Gently thread your piece of string underneath the log. Eyeball about one ninth of the dough log and think of the string as your knife. Holding one end of the string in each hand, pull in opposing directions to slice through one-eighth of the dough. Gently flip that first cinnamon scroll upright and use your hands to gently cup and mould it. Press it down a little so that it has a solid base, then place it into the prepared baking dish. Repeat with the remaining dough and scrolls.
Place a baking dish filled with boiling water at the bottom of the oven to create a steamy environment. This will help keep them nice and moist during baking.
Bake the scrolls for 30 minutes or until they feel firm to the touch and are lightly golden on top.
Whisk the ingredients for the icing together. I recommend adding a teaspoon or two of milk at a time until you reach your desired consistency – icing sugar needs less liquid than you might think. You can ice the scrolls warm or slightly cooled – it will melt into them if warm, or sit on top a little more if cooled. Store leftovers in an airtight container, and gently microwave leftovers to restore them to their former glory.