Adding whole corn kernels takes this cornbread to the next level of (corny) flavor!
Adjust oven rack to middle position and heat oven to 400 degrees. Spray 8-inch square baking pan with vegetable oil spray.
Helpful hint: Spraying the pan over the sink helps keep things clean.
In medium bowl, whisk flour, cornmeal, baking powder, baking soda, and salt until combined.
Add buttermilk, corn, and sugar to blender. Place lid on top of blender and hold lid firmly in place with folded dish towel. Process until combined, about 5 seconds.
Stop blender. Add eggs to blender, replace lid, and process until well combined (corn lumps will remain), about 5 seconds.
Pour buttermilk mixture into bowl with flour mixture. Use rubber spatula to stir until mostly combined (leave some streaks of flour). Add melted butter and stir until just combined and there are no streaks of flour. Pour batter into greased baking pan and smooth surface with spatula.
Place baking pan in oven and bake until cornbread is deep golden brown and toothpick inserted in center comes out clean, 25 to 30 minutes.
Use oven mitts to remove baking pan from oven (ask an adult for help). Place baking pan on cooling rack and let cornbread cool for 10 minutes.
Use oven mitts to flip baking pan over onto cooling rack to remove cornbread. Carefully turn cornbread right side up and let cool on rack for 10 minutes. Transfer cornbread to cutting board and cut into squares. Serve warm or at room temperature.
Run butter knife around edge of cornbread to loosen it from pan.
Gently flip cornbread out of pan and onto cooling rack.