Halliday & Matthiessen (2014: 394-5):
A measure item may be followed by a fully elaborated nominal group, as in a cup of that good strong Indian tea. It often happens that the Epithet is transferred to the Head, as in a strong cup of tea, although clearly it is the tea that is strong, not the cup. Similarly: a bloody good cup of coffee. It is partly the rather ambivalent nature of this structure, in which Head and Thing are separated, that causes this to happen; but it also arises because in many instances the Epithet could apply equally well to either, as in a cloud of thick smoke, a thick cloud of smoke, which provides the model for a strong cup of tea. (Classifiers, on the other hand, do not get transferred; we do not say a brown slice of bread.) Sometimes the Epithet belongs more naturally with the Numerative, as in a large cup of tea; but even here one can never have an Epithet that characterises the item in question in any way other than its function as a Numerative – one cannot say a blue cup of tea to mean ‘a cup of tea in a blue cup’. Finally, it is not unusual to have an Epithet in both positions, as in a thick layer of powdery snow, a plastic cup of red, watery punch.