Since most normal people take their desserts very seriously, a lot of pressure comes with cutting a cake. Some cake eaters specifically request edge pieces because they're icing fiends, while others ask for "just a small slice." If you're the one with the knife, the responsibility of getting everyone what they want falls on your shoulders. To avoid such a burden, you could make a policy that when it's your celebration, you're not in charge of cake cutting. That's effective and most good friends will respect the rule, but it's not full-proof. So, for those occasions when you can't wriggle your way out of cutting the cake, there is one hack you really need to have in your back pocket.