For the salad: Preheat the oven to 375 degrees F. Line a baking sheet with foil.
Arrange the bacon on the lined baking sheet without overlapping. Bake until crisp, about 15 minutes. Transfer the bacon to paper towels to drain. When cool, chop into pieces.
Toss the corn kernels in the olive oil. Season with salt and pepper. Place on a second baking sheet and bake until bright yellow and slightly charred, about 15 minutes. Let cool while you make the other ingredients.
Arrange the spinach, romaine and iceberg in a large foil pan or serving bowl, tossing them to mix. Sprinkle over the cheese and carrots. Sprinkle the bacon and corn over the salad. Serve immediately or cover with a damp paper towel and plastic wrap and refrigerate until ready to serve.
For the Greek yogurt ranch dressing: Meanwhile, add the buttermilk, parsley, dill, Worcestershire, pepper, paprika, cayenne, hot sauce, garlic and lemon zest and juice to a medium bowl. Whisk to combine. Add the mayonnaise and Greek yogurt. Whisk until smooth. Taste and adjust the seasoning if needed.