Preheat oven to 375°F. Spray square glass baking dish with cooking spray.
In food processor, blend 1 1/4 cups corn kernels with cornstarch until almost smooth.
Sautee green onions in melted butter, until tender. Whisk next 6 ingredients (eggs through pepper) in large bowl to blend. To this mixture, add corn puree, green onions, 2 tablespoon Parmesan and remaining corn. Stir until just blended.
Pour mixture into prepared dish. Sprinkle remaining Parmesan on top. Place dish in large roasting pan. Pour enough hot water into roasting pan to come halfway up sides of dish. Bake about 45 minutes. (Pudding will be just set.) Remove dish from water and let stand 5 minutes before cutting and serving.