Preheat oven to 425 degrees. Coat a 12 cup muffin tin with cooking spray; set aside.
In a medium bowl, whisk together flour, cornmeal, sugar, baking powder, salt, and baking soda.
Make a well in center of flour mixture. In the well, whisk together egg, sour cream, and corn. Mix with flour mixture just until incorporated (do not overmix).
Dividing evenly, spoon batter into prepared muffin pan. Bake until tops have browned and a toothpick inserted in the center of a muffin comes out clean, 17-20 minutes.
Let stand 5 minutes in pan; turn out onto a cooling rack.
Serve, or cool completely and store at room temperature in an airtight container, up to 2 days.
Little Helpers: My kids help measure the ingredients, stir and spoon the batter into the muffin cups.Make Ahead: You can make the dry mix ahead of time and store it in a sealed container. When you're ready to bake, all you have to do is add the wet ingredients, stir and pop them into the oven.