"Est-ce que tu aimes les noix au chocolat ?"

Translation: Do you like chocolate nuts?

[charnz]

In French when an item is described with aux, au or à la it means the second item is a crucial or defining ingredient to the first item. In this situation chocolate is a crucial/defining ingredient to the nuts, or in fact, chocolate nuts. For another example consider 'Un sandwich au fromage' = A cheese sandwich

[dimensional_dan]

Why isn't "Do you like chocolate with nuts?" a correct solution?

[Sitesurf]

"noix au chocolat" are nuts covered with chocolate.

[delapouite]

In this sentence nuts are "made" of chocolate. It's not the other way around, a chocolate bar with nuts inside.