Preheat the oven to 350°F/175°C.
In a stand mixer fitted with the paddle attachment, combine the flour, powdered sugar, baking powder, salt, and butter. Mix on medium speed until the mixture resembles coarse crumbs. Add the oil and orange juice, and continue mixing until the dough comes together—smooth, uniform, and slightly sticky.
Transfer the dough to a work surface, wrap in plastic wrap, and refrigerate for 2 hours or overnight. (Alternatively, freeze for 1 hour to speed up the process.)
Divide the chilled dough into three equal portions. Place a sheet of parchment paper on the work surface, lightly dust with flour, and roll out one portion into a thin rectangle. If the dough sticks, dust with a bit more flour.
Spread a thin, even layer of date spread over the dough, sprinkle nuts if using, and roll into a tight log using the parchment to lift and guide the dough. If it’s difficult to transfer, trim the parchment ends and move the log with the paper onto a baking sheet. Repeat with remaining dough.
Dust a sharp knife with flour and make shallow slits along the top of each log. Bake for 20 to 25 minutes, or until lightly golden.
Remove from the oven and dust with powdered sugar. Let rest for 5 minutes, then slice along the scored marks. Cool completely (20 minutes) before serving.