If you want baked mac and cheese, preheat the oven to 375 degrees Set out a 9 X 13 inch baking dish. For Stovetop Mac and Cheese, skip this step.
Shred both hard cheeses. Then set out the cream cheese to soften.
Place a 6 quart pot of heavily salted water on the stovetop. Set on high heat and bring to a boil. Drop the pasta into the boiling water. Stir well and cook according to package instructions. Usually 6-9 minutes for al dente. DO NOT overcook the pasta; it should still be slightly firm. Then scoop out 1 cup of pasta water for later use, and drain the pasta in a large colander.
Meanwhile, set another 4-6 quart pot over medium heat for the cheese sauce. Add 2 tablespoons butter to the pot, then whisk in 2 tablespoons flour. Continue to whisk for 2-3 minutes until the roux mixture is golden in color. (This ensures even thickening with no grainy texture. If the roux is too light, the texture won’t be completely silky.)
Whisk the half & half into the roux, stirring until there are no clumps. Then add the cream cheese and half of the shredded cheese. Stir to melt the cheeses. Add the salt, pepper, and garlic powder. Then add all remaining shredded cheese and stir until the sauce is completely smooth. Lower the temperature to make sure the cheese sauce doesn't boil.
Pour the drained pasta into the cheese sauce and stir to coat.
Stovetop Macaroni and Cheese: If you like creamy stovetop mac and cheese with a smooth silky consistent texture, you are done! The sauce does thicken a little as it cools, so if you want the sauce a little saucier, stir in ½ cup of the reserved pasta water.
Baked Macaroni and Cheese: If you want southern baked mac and cheese, stir in ¾+ cup of the reserved pasta water and pour the mac and cheese into the baking dish. Then toss the panko breadcrumbs with 1 tablespoon of melted butter, and sprinkle the breadcrumbs over the top. Bake for 15+ minutes, until the breadcrumbs are golden. The final product will have a crispy top and a thick saucy interior.
Quickie Cheat: If you are short on time, but want the crunchy breadcrumb top, you can toast the panko with the butter in a skillet. Place over medium heat and toss often. Then make the stovetop mac and cheese recipe. Pour the homemade mac and cheese recipe into a baking dish (or serving bowl) and sprinkle the crispy panko on top!