Which Beracha does one recite over bread that was placed in a toaster or in an oven until it became dry and crunchy?
Generally speaking, since a hard, crunchy texture is uncharacteristic of bread, bread that is prepared in this fashion does not have the formal Halachic status of bread, and therefore requires the Beracha of "Mezonot" rather than "Hamosi." However, this Halacha only applies to bread that from the outset was baked hard and crunchy, and thus never obtained the formal status of "bread" as far as Berachot are concerned. In the case under discussion, by contrast, the bread began as normal, soft, moist bread, and thereafter was placed in a toaster or returned to the oven to be dried and hardened. According to Halacha, the process of toasting or drying in an oven does not undermine the bread’s status with respect to Berachot. Therefore, even though the bread has been toasted and dried, it still requires the Beracha of "Hamosi" just as it did when it soft and moist.
It should be noted that this applies regardless of the bread’s size. Even a small piece of toast requires the Beracha of "Hamosi." Likewise, no distinction is made between different kinds of bread; whether one toasts pita, rye bread or any other kind of bread, the Beracha remains the same regardless.
Summary: Bread that was initially prepared hard crunchy requires the Beracha of "Mezonot," whereas regular, soft bread that was toasted or made crunchy in the oven requires the Beracha of "Hamosi."
