I have seen advice given by poskim to have in mind dessert cake in the beracha of Hamotzi in the beginning of a meal. What does this do? If cake is bread (according to some rishonim), then Hamotzi covers bread and if cake is mezonos, then Hamotzi doesn’t cover the cake unless the cake is being eaten for satiation and not just a sweet dessert.
Why do none of the poskim (that I’ve come across) recommend to have in mind that Hamotzi should for sure not cover dessert cake etc? Wouldn’t that make sure there is no doubt and require a beracha on the cake or is this a problem of a beracha she’eina tzericha, according to the rishonim who hold cake is bread?
It is true that this advice is given by a number of poskim, as mentioned by the Biur Halachah (168) in the name of the Chayei Adam (58:2). The Olas Tamid also writes that when one has explicit intention to include the mezonos, this helps, and this is also mentioned by the Mishnah Berurah in the name of Halachah Berurah (disciple of the Magen Avraham).
Rabbi Yechiel Michel Stern (Birkas Hanehenin p. 58) asks the question of how such intention will help: If the pas haba be-kisnin is not considered bread, it follows that the berachah of Hamotzi will not help.
Indeed, from the wording of the Magen Avraham (168:35) it appears that Hamotzi never helps for pas haba be-kisnin, and even a person’s explicit intention will not help for this purpose.
However, many authorities rule that bedieved, the berachah of Hamotzi helps for pas haba be-kisnin (Even Ha-Ozer 168:5; Kitzur Shulchan Aruch 56:1; Kerem Shlomo 168:5; Kaf Hachaim 168:43). This is also stated by the Ritva (Hilchos Berachos 2:18).
[However, see Maamar Mordechai 168:18.]
Based on the ruling that bedieved the berachah of Hamotzi helps, it can be explained that in cases of safek pas (a food that might be considered bread, but might not), it is permitted to rely lechatchilah on one’s explicit intention that the berachah should include the food.
Concerning the idea of qualifying the Hamotzi berachah so that it does not include the mezonos food, it is possible that this option is not preferred by poskim because: 1) it involves a dispute among authorities over whether berachos can be qualified or not (see Maadanei Asher, Siman 112, who cites a number of opinions both ways, though most poskim agree that berachos can be qualified), and 2) because it is a little complicated.
Furthermore, even if we assume that berachos can be qualified–see, for instance, Shulchan Aruch 174:4, concerning limiting the berachah on wine–it is possible that the Hamotzi berachah is different, because the idea is that a berachah is recited for the entire meal, and everything that is part of the meal is automatically included. One cannot limit the berachah so that is won’t apply to this dish or that, because it by definition includes the whole meal (though a cake isn’t quite the same).
Therefore, the best option is to make a berachah on a little mezonos before the meal, and the next best is to have explicit intent, which though slightly difficult to understand, is endorsed by the poskim.