In a bowl, combine semolina, plain flour, yeast and sugar. Add the butter and mix with your hands until fully incorporated and the mixture resembles small crumbs. Add rosewater and water, then knead until the mixture forms a homogenous dough. Cover with a lid or plastic wrap and leave to rest for 1 ½ to 2 hours.
Meanwhile, prepare the date filling. If your dates are a little dry, steep them in hot water for 10-15 minutes to soften, then drain. Remove the pits. Place the dates in a food processor with the melted butter and cinnamon. Process until you have a relatively smooth mixture, stopping to scrape down the sides as necessary. It doesn't need to be completely smooth mash, but it shouldn't have large chunks either. Transfer to the refrigerator. This makes it easier to fill the cookies later.
Preheat the oven to 180 °C. Line a baking sheet with parchment paper.
Divide the semolina dough into 20 pieces of c. 16 g each (1 Tbsp). Roll the pieces into balls.
Divide the date filling into 20 pieces of 7–8 g each (½ Tbsp). Flatten each into small discs about 2–3 cm in diameter (c. 1 in) and ½ cm (⅕ in) thick.
Using your hands, flatten each dough ball into c. 8–10 cm (3–4 in) diameter circles. It's best if they're slightly thinner at the edges than in the centre. I do this on my kitchen countertop, then use a dough scraper to lift the dough from the surface. You can also do it in the palm of your hand, if you prefer. Place a disc of date filling in the centre. Fold the edges in to enclose the filling. If you have a ma'amoul/kömbe mold (or a suitable alternative mold), place the filled dough ball in the mold, smooth side down. Press gently down, then release it by tapping the top of the mold against the kitchen counter. The cookie should come out. Transfer to the prepared baking sheet and repeat with the remaining pieces. If you don't have a ma'amoul/kömbe mold, shape the filled dough balls as nicely as you can and place them on the baking sheet with the seam side down. You can use a fork to create patterns, if you like.
Bake in the middle of the oven until golden, approximately 15 minutes. Leave to cool completely on a wire rack. Dust with a little icing sugar (powdered sugar) before serving.