Preheat the oven to 375 degrees.
Cook the pasta according to the directions on the package. Drain.
Meanwhile, heat the milk in a small saucepan over medium heat, stirring so it doesn't burn or boil.
Melt 6 tablespoons of the butter in a large pot and add the flour to make a roux. Cook over low heat for 2 minutes, stirring with a whisk to ensure the flour is cooked. After 2 minutes, stream in the hot milk and whisk, continuing to cook until thickened and smooth, about 2-3 minutes. Remove from heat, add the cheese, spinach and artichokes and season with 1 teaspoon salt and pepper. Add the cooked pasta and stir to combine. Pour into a baking dish.
Melt the remaining 2 tablespoons of butter, combine the melted butter with the panko crumbs, and sprinkle on the top of the baking dish. Bake for 30 to 35 minutes, or until the sauce is bubbly and the macaroni is browned on the top. Serve as needed.