In a large bowl, combine 31/2 cups flour, yeast, salt, sugar, spices and orange zest, whisking to combine.
With a wooden spoon (or, if using a stand mixer, with a dough hook), slowly add the lukewarm milk until absorbed, then add the eggs, mixing well. Add the butter, mixing thoroughly, then mix in currants until well distributed. If the dough seems very sticky, add the remaining 1/4 cup of flour.
Cover the bowl with plastic wrap and let rise in a warm place until doubled in volume, about 2 hours. Or, let dough raise overnight in the refrigerator, although not longer than 12 hours.
Prepare two baking sheets by lightly coating with baking spray or shortening, or covering with parchment paper.
Scrape dough onto a lightly floured counter and roll into a cylinder 18 inches long. Cut into 18 slices, 1 inch wide.
With floured hands, shape dough into a ball: Using one finger to support the dough, pull the edges around and under, repeating until you have a round shape. For an even smoother surface, lay the ball on an unfloured surface, cup it with your hand and, with gentle pressure, begin briskly rotating the dough for about 10 seconds. The friction of the dough against the counter will make the surface more taut and round.