According to [this][1] (which includes footnotes to the original sources) the bracha is Mezonot.

>There are two main instances where the bracha on bread is Mezonot:

>* when small pieces of bread are mixed with other ingredients, to the p[o]int that they are no longer recognizable as bread
>* when small pieces of bread are cooked
> When bread is 1) broken into pieces smaller than a kezayit, and 2) mixed
with other ingredients,<sup>3</sup> if the pieces are no longer recognizable as bread.
Generally, the bread loses its taste from being immersed in the other
ingredients, and the bracha becomes Mezonot.<sup>4</sup>
This is true even if the small pieces of "bread" are subsequently joined
together and made into one food that is larger than a kezayit.<sup>5</sup> For
>* an exotic dessert consisting of blenderized bread, mixed with apple
juice and brown sugar, and stuck together into squares covered in
>* turkey stuffing, which is made from bread that is broken up, mixed
with other ingredients, and then baked
> 3: Simply immersing bread in water alone does not have this effect, unless it is soaked to the point where the water begins to turn white. (OC 168:11)<BR>
> 4: Halachos of Brochos, ch. 26 footnote 44, citing Rabbi S.Z. Auerbach<BR>
> 5: The Laws of Brachos, pg. 264, citing Magen Avraham 168:26
> Cooking bread or changing its appearance by mixing it with other ingredients only affects its bracha when the pieces are smaller than a kezayit. Pieces of bread that are **larger** than a kezayit are still considered bread **even after** being cooked or altered. Their bracha remains Hamotzee.<sup>11</sup>
> 11: Orach Chaim 168:10

There are some more details, for example if the ground up bread is baked not cooked it may become Hamotzee again. (Stuffing is considered cooked not baked since it's wet, not dry like dough.)