To make the date paste, heat the ghee in a pan or pot, add the fennel seeds and the cardamom and the dates. Stir often until the dates soften.
Add the sesame seeds (if using) and stir to incorporate. Set aside to cool enough to handle.
To make the dough, stir the the flour, mahlab, salt, and nigella seeds to equally distribute.
Whisk the yeast and sugar in half a cup of the warmed milk, set aside for 5 minutes to activate the yeast.
Pour the yeast-milk mixture, and the remaining half cup of warm milk, and the melted butter over the flour mixture. Knead for 5 minutes. Let rest and rise for 20-30 minutes.
Alternatively, blitz everything in a food processor and knead in the nigella seeds manually.
Roll out the dough into a large rectangle about 1/4 inch thick.
Place the date paste between two large parchment sheets or clean plastic sheets and roll out to about the same dimensions of your rectangular rolled dough.
Remove the top sheet from the rolled date paste, then invert over the dough. Peel off the other sheet.
Cut the rectangle in half lengthwise, then roll each half from the middle long side into two long rods.
Flatten each rod slightly, brush the surface with egg wash, then cut the rods into 1/2 inch pieces.
Place, seam-side down on a baking sheet.
Bake in a preheated 360F oven for 15 minutes, then broil to a golden brown for a minute or two.
Delicious straight out of the oven, with a hot cup of tea.