Heat the oven to 375 °F. Get a large pot of salted water boiling.
Cook the pasta until very al dente (1–2 minutes less than package directions). Drain and set aside.
Make the roux: In the same pot over medium heat, melt butter, whisk in flour, and cook 1–2 minutes. Slowly whisk in milk and beer until smooth and thickened.
Flavor it up: Stir in mustard, garlic powder, and smoked paprika. Turn heat low, toss in cheeses a handful at a time, stirring until creamy—and season with salt and pepper.
Mix & bake prep: Fold rigatoni into the sauce so every tube is coated. Pour into a greased 9×13-inch baking dish.
Breadcrumb top (optional): Mix panko with melted butter and scatter over the pasta.
Bake 20–25 minutes until bubbly and top gets golden and crisp.
Let rest a few minutes, then serve. Watch it disappear.