Remove husks and silk from corn. Stand each ear upright in a wide, shallow bowl and use a sharp knife to cut downward, removing kernels. Use the back of the knife to scrape the cobs afterward, extracting the sweet corn "milk" for added flavor and moisture.
In a large bowl, whisk together flour, baking powder, baking soda, salt, black pepper, and cayenne (if using).
In a separate bowl, beat eggs until frothy (approximately 30 seconds). Add buttermilk and whisk until well combined.
Add corn kernels, diced onion, bell pepper (if using), and chives to the wet ingredients. Stir until vegetables are evenly coated.
Pour the wet ingredient mixture into the dry ingredients. Fold gently with a spatula until just combined. Avoid overmixing - small lumps are perfectly fine.
Heat 1/4 inch of vegetable oil in a large, heavy-bottomed skillet over medium heat until it reaches approximately 350°F (175°C).
Working in batches, drop heaping tablespoons of batter into the hot oil, flattening slightly with the back of a spoon. Leave enough space between fritters to enable easy flipping. Cook for 2-3 minutes per side until golden brown and crispy.
Transfer cooked fritters to a paper-towel-lined plate to drain excess oil. While still hot, sprinkle with a small pinch of sea salt to enhance the flavors.