Not sure about proportions, but baharat usually contains the following spices: allspice, black pepper, cumin, cinnamon, nutmeg, and perhaps cardamom. I would go heavy on the heavy on the allspice, less so on the rest of the ingredients, especially the nutmeg and cinnamon and cardamom (if you use it).
"By the fig, the olive..." Surat Al-Teen, Mecca 95:1"