Preheat the oven to 350 degrees Fahrenheit. Grease a 9x13 baking pan and set it aside.
Combine Muenster, Cheddar cheeses, and Monterey jack in a large bowl. Set aside.
Then prepare your elbow macaroni.
Bring 3 quarts of salted water to a boil in a large pot. Add pasta and cook according to directions on the box, about 8 minutes for al-dente noodles. Drain the noodles and add the drained noodles to a large bowl.
Pour melted butter over the noodles and stir into the macaroni.
Then add the half-and-half, eggs, half the shredded cheese, all of the Velveeta cheese, the seasoned salt, and pepper to the noodles, and stir to fully combined.
Pour this mixture into the prepared baking pan. Sprinkle the top with the remaining cheese mixture.
Bake in the preheated oven for about 30 minutes, until the edges are bubbling. Serve hot and enjoy.