Watch the video in the post above to see how the cake is rolled. It's best to roll it when it's warm out of the oven so that it doesn't tear or break. The warmer the cake, the more tender and soft it is to roll. But be careful to hot burn yourself! And allow the cake to cool completely before you add the filling so that the cream cheese doesn't melt. If the cake is warm at all and when you spread the filling, it will become soft and ooze all over the place. So patience is the key to making this roll cake pretty!
Also, don't mistake a 1/2 sheet baking pan with a jelly roll pan. The 1/2 sheet pans are generally 18"x13" while a jelly roll pan is 15"x10". You won't have quite enough batter or filling if using a 1/2 sheet pan. Another tip regarding roll cakes: take your time spreading the batter evenly on the pan before baking. An offset spatula helps make spreading easier.