Preheat oven to 375 degrees. Butter or spray a 3-quart glass or ceramic baking dish with non-stick spray, set aside.
In a skillet, cook bacon strips until crispy, drain, set aside to cool.
To make Béchamel Sauce: Melt 3 tablespoons butter in a medium saucepan and stir in the flour. Cook over low heat, stirring constantly for 2-3 minutes. Slowly add the heated milk and cook over medium heat, stirring constantly for 3-4 minutes. Reduce heat and simmer for 2-3 minutes, stirring constantly to prevent scorching. Remove from heat and add 1/2 teaspoon salt, pepper, parmesan and Tabasco. Stir until the cheese in melted. Cover and set aside.
Meanwhile, bring a large pot of water to a boil, add remaining 1 tsp salt and macaroni. Cook for approximately 5 minutes until the macaroni is very al dente. Drain the noodles and return to the pot. Immediately add the remaining 2 tablespoons butter, minced garlic and béchamel sauce. Toss well to coat noodles.
To assemble: Place 1/3 of the macaroni in prepared baking dish. Evenly top with 1/3 of the shredded cheddar, 1/3 of the Velveeta and 3 slices of bacon broken into small pieces. Repeat until all noodles, bacon and cheese are used. Top with the crushed French fried onions.
Bake covered with foil for 30 minutes. Remove foil and bake an additional 10-15 minutes or until the top begins to brown. Let sit for 5 minutes before serving.