If somewhere somebody exists who thinks that science can tell us whether we ought to prefer chocolate ice cream or pistachio then that theoretical dullard is guilty of "scientism".
Why do you think that when you think this:
On the other hand, science can inform us about objective morality and consciousness is probably nothing more than a function of the brain.
Morality is way more complex than someone choosing ice cream flavors. Don't you agree?
Don't you see this very point of view indeed implies that science can determine how and why someone chooses its ice cream?
Why do you think science is able to determine morality choices by scanning molecules from the brain but at the same time being unable to do the same about ice cream choices?