For the béchamel sauce, melt the butter in a heavy medium saucepan. When the foam subsides, stir in the flour and cook over low heat, stirring constantly, for several minutes. Slowly add the heated milk and cook over medium heat, stirring to prevent scorching. Remove from heat and add the salt, pepper, Tabasco and the Parmigiano, stirring well to melt the cheese. Cover and set aside.
Preheat the oven to 350 degrees. Butter a 3-quart glass or ceramic baking dish.
Fill a large pot with water and bring to a boil over high heat. Add the salt. Pour the macaroni into the rapidly boiling water, stir vigorously, and cook for approximately 5 minutes, until slightly undercooked and very al dente. Drain the macaroni, return it to the pot, and immediately toss with the butter and garlic. Add the sauce and toss again. Set aside.
Mix the cheddar processed cheese together. Place one-third of the macaroni into the baking dish. Sprinkle with one-third of the cheese. Top with another one-third of the macaroni and one-third of the cheese. Top with another one-third of the macaroni and one-third of the breadcrumbs, Parmigiano, and, seasoning salt together on a piece of waxed paper. Sprinkle over the top of the macaroni and cheese.
Place in the oven and bake for 30 to 45 minutes, or until bubbling and the top is beginning to brown. Remove from the oven and let sit for 5 minutes before serving.
Serves 4 to 6