Place diced bacon in a large skillet and cook over medium-high heat, turning occasionally, until evenly browned, 8 to 10 minutes. Drain bacon on paper towels and reserve 1 tablespoon bacon drippings.
Preheat the oven to 425 degrees F (220 degrees C). Spray an 8-inch square metal baking pan with cooking spray.
Stir cornmeal, flour, baking powder, sugar, baking soda, and salt together in a large bowl until well combined.
Whisk buttermilk and eggs together in a bowl. Stir in butter and the reserved bacon drippings. Pour buttermilk mixture over the dry ingredients, add bacon and corn, and stir until just combined. Spoon batter into the prepared baking pan, smoothing out the top with a spatula.
Bake in the preheated oven until top is golden brown and and edges start to pull away from the sides of the pan, about 25 minutes.
Transfer pan to a wire rack and let cool for 5 to 10 minutes. Cut into 12 squares and serve warm.