For the Cornbread: Preheat oven to 450 degrees. Coat bottom and sides of a 10-inch cast iron skillet with vegetable oil and heat in oven. In a medium bowl combine buttermilk and eggs, and stir. Add cornmeal, baking soda, baking powder, salt, and jalapeno peppers, while stirring briskly. Pour batter into hot skillet. Bake for 20 minutes, or until lightly browned.
For the Dressing: Combine ranch dressing mix, sour cream and mayonnaise and set aside. Place 1/2 of the crumbled cornbread in the bottom of a large serving bowl. Top with 1 can of pinto beans. Follow with 1/2 of the cheese, tomatoes, bell peppers, green onions, chile peppers, bacon, corn, and dressing mixture. Repeat ending with the dressing mixture. Cover and chill at least 2 hours before serving.