If pieces of Matzo are noticeable
Brocho before eating this: since the Brocho is questionable, it is preferable to first say a Brocho on some other food that requires a Hamotzi
If the pieces of Matzo are not noticeable
Brocho before eating this: Borei Minei Mezonos
Brocho after eating the proper shiur of this: Al Hamichya
Source: The Laws of B'rachos (page 373)