This has always confused me. One is not supposed to make unnecessary Berachoth, so one should "have in mind" to eat all of the foods that will be served in the meal when one begins the meal and makes his first Berachah/oth. Yet, one is supposed to make a separate Berachah on dessert, because it is clearly (really?) not included in the actual meal that one has in mind.
Perhaps I am mistaken as to the underlying reason, so first, is the above correct?
Second, if I do specifically have in mind to exempt dessert with my Motzi, is that effective?