Preheat the oven to 425 degrees F (220 degrees C).

Place sausages in a dry pan over medium heat until they start to sizzle. Use a spoon or flat wooden spatula to break them up as they cook. Continue to cook until browned and crumbly, 10 to 12 minutes. Remove from the heat. Drain grease if desired.

Combine cream cheese, sour cream, 4 ounces grated Cheddar, thawed corn, cooked sausage, fire-roasted tomatoes with chiles, Hatch chiles, jalapeño peppers, green onions, salt, pepper, and cayenne in a large bowl; mix until thoroughly combined. Transfer into a baking dish and smooth out the top. Top with remaining Cheddar, and cayenne.

Place the baking dish on a sheet pan and bake in the center of the preheated oven until cheese is melted and dip is bubbling around the outside, about 30 minutes.

Sprinkle green onions over top before serving.