Preheat the oven to 450 degrees F. Prepare a 10-inch cast iron skillet by heating it in the oven for 5 minutes. Remove the pan from the oven, add the butter, let it melt and set aside.
Put the eggs and corn in the bowl of a food processor and pulse until the corn is slightly smooth. Add the cornmeal, flour, sour cream, sugar, baking powder and salt and pulse until smooth. Transfer the mixture to a bowl and fold in the jalapeno and melted butter.
Pour the batter into the skillet and bake until golden brown and a skewer inserted in the center comes out clean, about 20 minutes. Serve warm or room temperature.