Remove 2 tablespoons of the drained Mexican corn to a small bowl; set aside.
Preheat oven to 375°F (190ºC). Butter a 12-inch cast iron skillet or a 9X13-inch baking dish; set aside.
In a medium mixing bowl, mix together 4 ounces cream cheese and 1 cup of mayonnaise until smooth and well combined.
To the mayo mixture, stir in 1 1/2 cups of Mexican cheese, 1 cup Parmesan cheese, remaining 3 (11-ounce) cans drained Mexican corn, 1/2 cup green onions, and 6 slices cooked and crumbled bacon until evenly combined.
Spread evenly in the prepared baking dish, sprinkle top with remaining 1 1/2 cup Mexican cheese, and bake, uncovered, in the preheated oven until hot and bubbly, 35-40 minutes.
Top with green 3 tablespoons green onion, 2 slices cooked and crumbled bacon, 2 tablespoons of the set aside Mexican corn (from above).
Notes
Can This Recipe Be Cut in Half? The recipe as written below make a generous 9x13 inch baking dish or large skillet portion. This is great when you're having a crowd or need an appetizer for a potluck.
If you're serving a smaller group or just watching football with your hubby, the recipe is easily cut in half and baked in an 8x8 casserole dish.
Optional Add-Is: This is great with chiles. For convenience, try adding drained canned Hatch chiles, or mild green chiles. They are available canned and come already chopped. Be sure to drain the can before adding to the dip. They don't have a lot of liquid in the cans but I just don't want to dilute the wonderful creaminess of this dip. Of course, you can also add homemade roasted and peeled poblano peppers too, if you have a little extra time to prepare them.
Optional Toppings: This already has a thick cheesy topping but it can also be topped with chopped fresh cilantro, sour cream, diced tomatoes, red onions, green chilies (canned or fresh), chopped red or orange bell pepper, and or a little extra corn! Any way you serve this appetizer it will be delish.