Would the Haste Spell allow you to cast a second, singular weapon attack effecting cantrip (such as Greenflame Blade)?

So the Haste spell in 5e says that the targeted creature

gains an additional action on each of its turns. That action can be used only to take the Attack (one weapon attack only), Dash, Disengage, Hide, or Use an Object action.

This means I technically have a second action, so would that allow me to use the Greenflame Blade cantrip a second time in the same turn (once with the actual action, once with this action) as the cantrip applies to one weapon attack in a similar fashion as a Paladin with Haste could apply Divine Smite onto the Haste-given attack?