If you are going to top them in the future, what I do is cut them into bars first and then top each individual bar. Otherwise the toppings get in the way while cutting.
The cutting process is kind of laborious. If I have the time, I will freeze them for half hour before cutting. I put the whole thing on a large cutting board and slice down with a large knife and then drag the knife toward me. If I slice down and then pull the knife back up, bits of crust will act as abrasives and ruin the look. Then I wipe the knife clean after each slice. If you got the cheesecake nice and firm in the freezer, you can run your knife under very hot water, then dry it, and it will give me an even cleaner cut. But you still have to clean the knife, then heat it up and dry it again before the next cut.
