Combine milk and cream in a heavy saucepan and bring to a boil over high heat, whisking occasionally. While whisking, pour in cornmeal in a steady stream. Whisk vigorously to incorporate the cornmeal, about 1 minute. Remove from heat and set aside to cool to room temperature.
Transfer cornmeal mixture to the bowl of a stand mixer fitted with a paddle attachment. Add eggs, 2 tablespoons butter, sugar, baking powder, and salt. Mix on medium speed until uniform and aerated, about 15 minutes. Mix in the corn by hand.
Preheat the oven to 375 degrees F (190 degrees C).
Lightly butter a round 1 1/2-quart casserole dish with remaining 1 tablespoon butter. Pour batter into the casserole dish.
Bake in the preheated oven until golden brown and puffy and a toothpick inserted in the center comes out clean, about 30 minutes.