I hope this is the right forum to ask this...
I am wondering if I could replace whites with yolks 1:1 in a white cake recipe? I have a recipe I would like to try but would like to use the yolks so I can use the whites for my SMBC, lol. I don't mind if the cake is more yellow than white.

I don't know the whole lowdown on cake chemistry, but I can tell you that yolks are not substitutable for whites, because yolks contain fat and whites don't. Also whites expand when they cook and yolks don't so much. So you wouldn't end up with a yellow cake instead of a white one. That said, I would be tempted to experiment (on a small scale, before going whole hog) to see what happens - you'll probably get a dense yellow-colored cake that might even be delicious!