Size of pieces of fish for baking
In general, the size of the cut has the biggest impact on how long the food will cook. A thinner slice of salmon will cook much more quickly than a thicker cut with the same surface area. Cutting the salmon too thin with a large surface area can also lead to over-seasoning, which will overpower the delicate salmon flavour. I prefer to cut salmon into evenly-sized squares approximately 2 cm thick, possibly thicker (I do not normally measure). Using a whole salmon can be good if you are an experienced cook, however it can be difficult to ensure all the small bones, guts, etc have been removed, and some find the head to be unappetizing. If going that route, it is also important to remember to season underneath the skin, as skin creates a waterproof barrier that will not allow flavours from spices to seep through, and normally one would stuff the opening you cut for removing the bones with seasoning as well (try placing thinly sliced pieces of lemon inside along with whatever seasoning blend you like before baking).