Combine the grated sweet potatoes and carrots, then add the cilantro, scallions, flour, eggs, ginger, salt, pepper, and cinnamon. Mix everything together until the mixture has a sticky but not gluey consistency. You may have to adjust the flour and egg quantities, depending on how big your eggs are.
Heat the oil in a deep 12-inch nonstick skillet over moderately high heat until hot but not smoking. Using a slotted spatula and working in batches of 4, spoon 2 tablespoons of the potato mixture per latke into the oil and flatten it to a 3-inch round. Reduce the heat to moderate and cook until golden, about 2 minutes on each side. Transfer the latkes to paper towels to drain.
Repeat until the batter is used up, adding more oil as needed. Remember to bring the oil back up to a fairly hot temperature before adding more latkes; if the oil isn’t hot enough, they’ll cook more slowly and soak up more oil.
If you plan to serve the latkes warm, shuttle them to a preheated 300°F oven. Serve with homemade applesauce!