How to Make It
In a large saucepan of salted boiling water, cook the corn until crisp-tender, 3 to 5 minutes. Transfer to a plate and let cool completely, then cut the kernels off the cobs.
In a large bowl, beat the egg with the water. Sift the flour, salt and baking powder over the egg and whisk until a batter forms. Stir in the corn kernels and scallions.
In a large nonstick skillet, heat the 1/4 cup of canola oil until shimmering. Spoon a scant 1/4 cup of the batter into the skillet for each pancake and cook over moderate heat until browned on the bottom, 1 to 2 minutes. Flip the cakes and top each with a piece of cheese. Cook until the cheese just starts to melt and the corn cakes are cooked through, about 2 minutes longer. Transfer the corn cakes to a serving platter and season with black pepper. Repeat with the remaining batter. Serve warm.