To get a Mongol North Africa, have Mongke not get the dysentery that killed him OTL. Have him live until 1270 or so, and North Africa and al-Andalus will be firmly under the Mongol thumb.
Seraphiel
Banned
I seriously doubt the Mongols would have gotten to Iberia, fra to far away, the Mongols had little sea power in the Med., and they had to cross the vast distance of north africa, supply lines would be simply to long. Though an occasional raid probably would have occured if the Mongols had gotten to Morroco.