AI am wanting to bake a half sheet cake with half yellow and half chocolate. How do you you do this.

If you are talking about a side by side - People do that all the time...

They do make an apparatus that one can use...

or you can just do it the old fashioned way and pour each on opposite sides...

If you mean top and bottom... I would imagine there is a way to do it, but I am unsure of it without using two cake pans...