I recently heard that Sephardim treat Matza as Mezonot throughout the year except on Pesach. Why is this?

Dough that is baked to a crunchy pastry, for instance crackers, is called in Halacha “Pat Habaa Bekisnin (PHB)” and its Brachah will be Mezonot. For that reason Matza qualifies PHB and caries the same Brachah. Whoever, on Pesach it is the bread of the week and therefore will be Hamotzi. The Ashkenazi custom is to say Hamotzi all year round since we always eat it as bread in a meal. (Vzot Habracha P.21).