In a large bowl or stand mixer, whisk together yeast, 1 tablespoon date sugar, and non-dairy milk. Set aside.
In a small bowl, whisk together water and milled flax seed. Set aside.
In a medium bowl, whisk together remaining bun ingredients, except currants or raisins.
By now, the yeast mixture should be nice and bubbly. Add the flax seed mixture.
Start adding the flour mixture a spoonful at a time, until it is all incorporated.
If kneading by hand, knead for 10 minutes. If using a stand mixer, knead for 5 minutes.
Cover and let sit to rise in a warm place, until doubled in size (1-2 hours).
Punch down and let sit for 4 minutes.
Knead in the currants.
Divide into 16 balls and place on a baking sheet.
Cover and let rise again until doubled again (30-40 minutes).
Preheat oven to 400 degrees F.
Deeply score the top of each bun with a sharp knife or razor blade in the shape of a cross.
Bake for 10-12 minutes, or until the buns are lightly browned.
As soon as the buns are out of the oven, glaze with date syrup.
Let buns cool completely on a wire rack.
Meanwhile, combine raw cashews and water for the frosting in a high speed blender until smooth. Let the cashews soak in the water for about 1/2 hour if you have a regular blender.
Pipe the frosting into the crosses on the buns.