Preheat oven to 350 degrees F (175 degrees C).

In a medium bowl, beat butter with electric mixer until creamy. Add masa harina and water and beat until well combined.

In food processor or blender, process corn in short pulses to coarsely chop. Leave several pieces of whole corn. Stir the processed corn and the cornmeal into the butter mixture.

In a separate bowl, stir together sugar, cream, salt and baking powder until well combined. Stir sugar mixture into butter mixture and pour all into a 9x9-inch baking dish. Cover with foil.

Line a roasting pan with a damp kitchen towel. Place baking dish on towel, inside roasting pan, and place roasting pan on oven rack. Fill roasting pan with boiling water to reach halfway up the sides of the baking dish. Bake 50 to 60 minutes, or until pick inserted in center comes out clean. Remove baking dish from water bath and let rest 10 minutes. Serve using ice cream scoop or large spoon.