Mix together the spices for the cake spice mix. You will only need 1 1/2 teaspoons of the spice mix for recipe; store the remaining spice mix in an airtight container at room temperature for up to 6 months.
To make the date ﬁlling, grind the dates and oil in a stand mixer ﬁtted with a food grinding attachment (ﬁne grind) or in a heavy-duty food processor. If using a stand mixer, alternate between adding the dates and oil. If you’re using a food processor, before you add any dates, rub oil on the blade and inside of the bowl. Once processed, oil your hands and knead the cake spice mix into the dates.
To make the dough, combine the sugar and water in a small saucepan over medium heat. Bring to a full, rolling boil (occasionally giving the pan a swirl); boil 1 minute and then turn off the heat. Cool 5 to 10 minutes.
Combine the oil and clariﬁed butter in a separate small saucepan and cook over medium heat until the butter is just melted, about 2 minutes; cool slightly.
Put the ﬂour in a large bowl and whisk in the yeast. Use a wooden spoon to gradually incorporate the oil mixture, then gradually incorporate the sugar syrup. Knead the dough until it comes together nicely into a shaggy dough, adding up to 4 tablespoons more ﬂour as needed (when done, the dough will be soft and should look smooth, shiny, and slightly oily). Cover the dough, put it in the freezer to stiffen slightly, about 5 to 10 minutes, and then knead it again for a couple minutes.
Preheat the oven to 350F; line 2 large baking sheets with parchment paper or Silpat liners.
To shape the cookies with a ma’amoul mold (see note below), measure 1 slightly scant tablespoon of dough and roll it into a ball; slightly ﬂatten it with your hands, then press it into the bottom and up the sides of the mold. Measure 1 teaspoon of the date mixture and roll it into a ball; slightly ﬂatten it and gently press it into the dough in the mold. Measure 1 slightly scant teaspoon of dough, roll it into a ball, slightly ﬂatten it, then put it on top of the date mixture in the mold; use your ﬁngers to press the dough on the top into the dough on the sides. To remove the cookie from the mold, hold the mold by the handle and tap the flat rim on a secure surface; the cookie will drop right out.
Arrange the cookies on the baking sheets about 1/2 to 1 inch (1 1/4 to 2 1/2 cm) apart (if you use 2 half-sheet pans, the cookies should all ﬁt on 2 pans; if you use smaller pans you will need to cook them in 2 batches). Bake until light golden brown on the bottom, about 20 to 25 minutes, rotating the trays once.
Cool completely, and then dust with the powdered sugar. To store the cookies, package them layered between parchment paper in an airtight container.