Mix together the spices for the Cake Spice Mix. You will only need 1 ½ 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 canola 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 canola 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, 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 oven to 350°F (175°C); line 2 large baking sheets with parchment paper or silpat liners.
To shape the cookies with a ma'amoul mold, 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.
To shape cookies by hand (as seen in the photo), take a small handful of dough (about 1 1/2 tablespoons) and roll it into an egg shape. Gently insert your finger into one end (don't go through to the other side), rotating the dough as you do so; you will end up with a little well. Fill this well with about 1 teaspoon of filling and pinch the end to seal. Use your hands to gently shape it into a circle and then slightly flatten the circle into a disc. Use a fork to make a decorative crosshatch pattern on top.
Arrange the cookies on the baking sheets about ½ to 1 inch (1.25 to 2.5 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.