Preheat the oven to 350 degrees F. Butter and flour a muffin tin and set aside. Or you could use muffin liners; make sure you spray them with a cooking spray.
In a medium bowl, whisk together the flour, cornmeal, baking powder, baking soda, and salt.
Whisk in, sour cream, milk, and lightly beaten eggs until well combined
Then, add crushed pineapple, jalapenos and melted butter
Pour batter into prepared muffin pan. Bake 15-18 minutes or until light golden brown and toothpick inserted in center comes out clean.