Preheat oven to 325 degrees F.

Cook the macaroni to al dente, according to package instructions. Drain and set aside. Shred cheeses and set aside.

Make the sauce: Melt the butter in a medium saucepan over medium heat. Blend in the flour, garlic powder, salt, and pepper. Cook for 2 minutes.

Slowly add the milk and half and half, stirring constantly and bring to a simmer and simmer 1 minute. Remove from heat and stir in truffle oil, and then shredded cheddar and gruyere cheeses, stirring just until melted.

Combine: Add the cooked macaroni noodles and toss to coat. Pour half or the pasta mixture into a greased 9x13 baking dish. Sprinkle 1/4 cup parmesan cheese over the top. Add remaining pasta and sprinkle with remaining parmesan cheese.

Breadcrumb Topping: Add panko, melted butter and truffle oil to a skillet (or the saucepan used to cook the pasta). Cook over medium-high heat, stirring constantly, until the crumbs are golden brown. Evenly sprinkle over the mac cheese.

Bake 15-20 minutes or until bubbly. Serve warm.