Hello,
I've never had a request or an order for this but wanted to see if it would work for my own daughters birthday cake since the design I planned is for one 10inch square but I forgot that some family members would prefer chocolate cake, though my daughter would like white.
Can I use a strip of parchment paper in the middle of a 10inch square pan to fill one side with chocolate and one side with vanilla??
Not sure if parchment would work or not, if you know for sure could you help me out? If there is something else I could use easily to separate the two in one pan, what would it be?
Thank you so much!

I've just cut a piece of a cardboard cake board to fit the width of the pan and stuck it in there (if it's snug, it will stand there). Then i put the two batters in carefully on either side, and then pull out the board. The only thing to keep in mind is that white and chocolate cake don't usually bake up the same height, at least not for me, so I have to level them.

Okay thank you, my chocolate cakes don't seem to rise as much as others sometimes but that is okay too, it'll be leveled and layered.
I will just try what you said, thank you!

I just pour them both in at the same time, they stay on their own sides. I agree, they don't bake at the same time. I always struggle with this and have to trim some cake off the top when it's done.

I pour both flavors in at the same time, also. Just start pouring toward the middle and form a line then keep pouring. It works! the chocolate doesn't bake as high, but i usually just put more icing on the chocolate side to build it up a little.

Thank you! I'll probably make a test cake to see how I do and also see about how much less my choc. cake will rise compared to the other side. Oh! duh, I can try this for Easter I guess. I keep forgetting about our own Easter cake. lol
Thank you!

Are you guys all baking scratch? Because my choc always rises higher than my white cake; but I'm a mix baker.

And I'm in the "just pour them in" crowd.

Usually I use doctored mixes or whatever that are called. I actually just got done writing down a scratch recipe that I've been wanting to try. So I hope to use it for the Easter cake... which is really going to be a practice cake for her birthday on the 9th.

Depends on the cake - I do some scratch - but mostly dr'd mixes. My chocolate does raise higher than the white, too.