Preheat an electric griddle to 380 degrees. or place a griddle pan or large skillet over medium-high heat.
In a medium bowl, whisk together cornmeal, sugar, and salt. Add boiling water, and mix to combine. The batter will be thick. Using a tablespoon, drop the batter onto the griddle 2 inches apart for each johnny cake. Let cook for 6 minutes, turn and cook 5 minutes more.