need acceptable substitute!

[luv2cook]

I want to make these cupcakes (banana cupcakes)for VD tom. and I am short on the yogurt. Is there anything that I can add to make it a complete 1/4 cup? or should I find something else?

[djoygirl]

you can substitute any kind of sour cream, and probably even cream cheese

[luv2cook]

thank you thank you! Now, if I can just make ONE banana make 1C of puree!