Step 1

Preheat oven to 400°. Generously coat a standard 12-cup muffin pan with nonstick spray.

Step 2

Whisk flour, cornmeal, sugar, baking powder, baking soda, kosher salt, and pepper in a large bowl. Stir in 1½ cups corn.

Step 3

Lightly whisk eggs and egg yolk in a medium bowl, then whisk in sour cream, milk, and butter.

Step 4

Create a well in the center of dry ingredients. Pour egg mixture into well and stir with a wooden spoon until batter is just combined.

Step 5

Divide batter among prepared muffin cups. Top with remaining ½ cup corn, then sprinkle with sea salt.

Step 6

Bake muffins, rotating pan halfway through, until tops are golden brown and a tester inserted into the center comes out clean, 18–20 minutes. Let cool slightly in pan. Transfer muffins to a wire rack and eat while warm or let cool completely.

Step 7

Do Ahead: Muffins can be made 1 day ahead. Store in an airtight container at room temperature.