Whisk the flour, cornmeal, baking powder, sugar, and salt in a medium bowl until ingredients are evenly mixed. Add the corn kernels and stir to coat.
In another bowl, whisk together the sour cream, water, eggs, and melted butter. Form a well in the center of the dry ingredients and pour the wet into the center. Stir gently to form a thick batter. It may look a little lumpy, but don't worry this is how it is supposed to be.
Over medium heat, melt 1 teaspoon of butter into a cast iron skillet. When the butter is hot start frying the hoecakes. Using a 1-ounce ice cream scoop, drop the batter into the pan, leaving enough room for the cakes to spread. Sprinkle with fresh corn. Allow cooking until bubbles start to form around the edges and the holes stay when the bubbles pop for about 2-3 minutes. Flip and cook for an additional 1-2 minutes until golden brown.
Remove from the pan and place on a cookie sheet lined with paper towels. Continue frying in batches until all the batter is gone. Add more butter to the pan in 1 teaspoon increments when the pan starts to look dry.