Preheat the oven to 350ºF and grease a 9" x 13" casserole dish with coconut oil. Drain the soaked millet in a strainer and rinse well. In the bowl of a large food processor fitted with an "S" blade, combine the drained millet, 1 pound of the thawed corn, 1 cup water, melted coconut oil, sugar, salt, baking soda, and vinegar. Process well until a relatively smooth batter is created, which should take about 2 minutes. Add in the remaining 1 pound of thawed corn and pulse a few times to combine-- you want to leave plenty of texture in this dish.
Pour the batter into the greased casserole dish and bake at 350ºF until the top is lightly golden, about 45 minutes. Allow to cool at least 15 minutes before serving. Leftovers can be stored in an airtight container in the fridge for up to one week.