I tend not to make mezonot when having dessert as I usually have dessert to be satiated, rather than for the sweet taste and also if its not Pas HaBah Bekisnin.
Is this the correct thing to do?
Also, would there be a requirement to make a bracha on wafers or cookies which are eaten after having the main dessert?
The question of making a beracha on a mezonos dessert has been discussed at great length by Poskim.
According to the Mishnah Berurah one only makes a berachah on fruit-filled pies, which are considered “real” pas habah bekisnin, while most other cakes are too similar to bread to make a new berachah over (see Chayei Adam 43:7; Biur Halachah 168:8). Rav Moshe Feinstein, however, ruled that as long as flour and water are not the majority ingredients (true for most cakes today), mezonos is recited over them when served as dessert (Iggros Moshe, Orach Chaim 3:33; see also Vezos Habrachah p. 229).
There are different customs in practice, and each does according to his custom.
Yet, in your case, if you are eating the cake while still hungry and for purposes of satiation, no berachah should be recited (see Mishnah Berurah 168:41).
Wafers are a case of pas habah bekisnin according to all opinions, and when eaten for dessert (at any stage) a berachah is made.