Dunkin’ Donuts is quietly testing “Donut Fries” as a side in Boston. The trial follows Taco Bell’s rollout of Nacho Fries, which the chain announced last month had became its biggest-ever product launch. So, Dunkin’ “doughnuttified” its version by dusting them with cinnamon and sugar. Dunkin’ says they “pair perfectly with Dunkin’ Donuts’ signature beverages.”