I roasted a ton of sweet potatoes today. Then, I started by adding 1/4 cup of cocoa powder per potato. I will admit that if you start with 1/4 cup cocoa for every sweet potato, the essence of sweet potato lingers, but it is a delicious sort of lingering.
Just add a dash extra of vanilla or more cocoa and that sweet potato flavor will fall away. It depends on how much you or your little ones like potatoes...I have a kid who hates potatoes of all sorts.