Mix the granulated sugar and ground cinnamon in bowl then set aside.
1/2 cup granulated sugar, 1 tablespoon ground cinnamon
In a deep fryer or large pot, heat oil to 350°F
Oil for frying
Carefully add a few pieces of duros to the hot oil. They will puff up quickly, so fry them in batches for about 20-30 seconds until puffed up, golden and crispy.
4 oz spiral shaped duros
Remove the spirals from the oil using a slotted spoon and place them on paper towels to drain any excess oil.
While the twists are still warm, toss them in the cinnamon-sugar mixture until evenly coated. Allow them to slightly cool down before serving.