Halacha Orach Chaim 168

There are several variables to take into account before reciting a Bracha and eating Challah Kugel.

Scenario 1
Challah is broken up and placed in a pan, and other ingredients are poured into the pan as well. The mixture is then recooked.

If pieces of Challah are broken smaller than a Zayis, which is approximately the size of two regular chocolate chip cookies, a Mezonos should be recited. If the Pieces are broken down, but larger than a Zayis, Hamotzei is recited.

Scenario 2
Challah was broken down, and placed into a pot with other ingredients, but was not recooked on the stove or in the oven.

The only time a Mezonos would be recited, is if the pieces were broken down smaller than a Zayis, and it does not look like bread. If it looks like bread, or the pieces are larger than a Zayis, Hamotzei is recited.

Scenario 3
Challah is broken down and other ingredients are not added, although the pieces are spiced.

In such a case, a Hamotzei is recited, even if the Challah is ground to look like flour.

Biyur Halacha brings a novel idea. If the Challah Kugel consists of large piece that are recooked, but there are also smaller pieces in the same pan, one can eat the smaller pieces, and recite a Mezonos on them, even though the majority of the kugel requires a Hamotzei. However, if one washed and ate the larger pieces, he obviously will not recite a Mezonos when eating the smaller ones as well.