Preheat oven to 450°. In a 10-inch cast-iron skillet, place 2 tablespoons oil. Place skillet in oven until very hot, about 8 minutes.
In the container of a blender, place ½ cup corn kernels; process until smooth. Set aside.
In a medium bowl, whisk together cornmeal, flour, baking powder, salt, and sugar. Stir in ½ cup corn kernels. Make a well in center of cornmeal mixture; add buttermilk, eggs, blended corn, and remaining 2 tablespoons oil, stirring just until moistened. Carefully spoon batter into hot oil. Sprinkle with remaining ½ cup corn kernels.
Bake until golden brown and a wooden pick inserted in center comes out clean, 15 to 17 minutes. Let cool in pan for 5 minutes. Remove from pan, and let cool on a wire rack for 10 minutes. Serve warm with butter.
Recipe by Taste of the South at https://tasteofthesouthmagazine.com/fresh-corn-cornbread/