Preheat Oven: Preheat the oven to 350°F (175°C).
Cook Pasta: Boil macaroni in salted water according to package directions until al dente. Drain and set aside.
Prepare Cheese Mixture: In a large mixing bowl, combine cheddar, mozzarella, and Swiss/Gouda cheese. Add eggs, evaporated milk, heavy cream, salt, pepper, nutmeg, and garlic powder. Whisk until smooth.
Combine Pasta and Cheese: Fold the cooked macaroni into the cheese mixture, making sure every piece is coated. Stir in finely chopped Scotch bonnet pepper if using.
Transfer to Baking Dish: Grease a 9x13-inch baking dish and pour the macaroni mixture into it. Smooth the top. Sprinkle breadcrumbs and extra cheese if desired.
Bake: Bake in the preheated oven for 30–40 minutes, or until the top is golden brown and the center is set.
Cool and Serve: Let the dish rest for 5–10 minutes before serving. Enjoy warm.