Preheat oven to 375*. Butter a 9 x 13-inch baking dish; set aside.
Whisk together cornmeal, milk, butter, 3 cups water, 1 tablespoon salt, and a pinch of pepper in a medium saucepan.
Bring to a boil over medium-high heat, whisking constantly. Reduce heat to medium. Cook, whisking constantly, until mixture has thickened, 6 to 8 minutes. Transfer to a large bowl, and let stand 15 minutes.
Whisk baking powder into cornmeal mixture. Whisk in eggs. Pour into prepared baking dish. Bake 20 minutes.
Reduce oven temperature to 350* and bake until puffed, golden and set in center, about 20 minutes more.