Preheat oven to 340 degrees F (170 degrees C). Grease and flour a 10-inch round cake pan.
Blend cornmeal, sugar, milk, coconut milk, flour, eggs, and vegetable oil in a blender until smooth; add baking powder and blend to integrate. Pour the cornmeal mixture into the prepared cake pan.
Bake in the preheated oven until a toothpick inserted into the center comes out clean, 30 to 40 minutes.