Preheat the oven to 350℉ (180℃). Grease your casserole bowl and set aside.
Strain the liquid from the can of corn into a bowl. Pour it into a measuring cup; if it doesn't reach the one-cup mark, add water until it does.
Return the water to the bowl, then add the egg and cornmeal. Mix thoroughly and set aside.
Melt the butter in a saucepan, then add the green onion, onion, bell pepper, salt, and ground scotch bonnet pepper (optional). Stir for 2-3 minutes or until the veggies are tender.
Add the milk, bring to a boil, and quickly add the cornmeal and egg mixture. Reduce heat to low and cook for about 4 minutes, stirring frequently.
Add the canned corn and continue simmering for another 5 minutes or until the mixture pulls away easily from the sides of the pot.
Finally, add ½ cup of grated cheese, parsley, and sugar (if desired) and mix well.
Transfer the corn casserole into the prepared baking dish and top with the remaining cheese.
Bake until the top is lightly brown, about 30-40 minutes, and the cheese is bubbly.
Let it cool for a few minutes before serving hot so the cheese has time to firm up just enough.