Does the extra attack allow you to cast Green Flame Blade and make the second attack?

@JeremyECrawford Does the extra attack feature of Bladesong Wizard allow you to cast Green Flame Blade and also make the second attack?

— Some sort of cat (@Goldleej) November 12, 2015

Extra Attack requires the Attack action. Casting a spell (cantrips included) requires the Cast a Spell action. #DnD https://t.co/gxlZIGTx9W

— Jeremy Crawford (@JeremyECrawford) November 12, 2015