When you cut a cake to produce a slice like the one in the picture above, you're actually performing a non-optimal cut. Why? If you don't eat the rest immediately, the inner surfaces of the remaining cake are exposed to the air, drying it out.
In a 1906 edition of the journal Nature, a mathematician explained the optimal, scientific way to cut a cake to ensure it doesn't dry out. As Numberphile explains in the video below, the mathematician proposed a series of straight cuts across the entire cake. With this method, the remaining uneaten pieces can be pushed together so that no surfaces are exposed to the air for a prolonged period of time.
To understand how to cut your cakes the scientific way, view the video below.