@CLHS68 wrote:
I would think you could use butter instead of oil.
Yes you can. From Livestrong.com
When swapping out butter for vegetable oil in a cake mix, melt the butter first in the microwave so that it is liquefied. Do this in 15-second increments to avoid burning the butter, which can negatively affect its flavor. Use either the same amount of butter or about 20 percent more than the directions call for to make up for the difference in the fat content between butter and vegetable oil. If the mix calls for 1 cup of vegetable oil, then substitute 1 cup of melted butter and just under a 1/4 of a cup of melted butter.
“All you have to do, I tell myself, is keep your mouth shut and look stupid. It shouldn't be that hard.”
― Margaret Atwood, The Handmaid’s Tale