What's the cake taste? What flavour is the cake? Which one?
I need the question whose answer is :
It is chocolate and truffle.

Thanks

Question

What's the cake taste? What flavour is the cake? Which one?
I need the question whose answer is :
It is chocolate and truffle.

Thanks

Answer

We wouldn't say "what's the cake taste"
we would say "What flavour is the cake" or 
"What does the cake taste like" - this is asking about the flavour of the cake or
"how does the cake taste" - this is asking if the cake tastes good

Answer

I would say "what kind of cake is it?"