Preheat oven to 375°F (190°C). Cook macaroni in salted water or beer until al dente. Drain.
Cook bacon until crisp, about 8–10 minutes. Drain, reserving 1 tbsp fat.
Melt butter in skillet with bacon fat. Whisk in flour and cook 2 minutes.
Gradually whisk in beer and milk. Cook until thickened, 5–7 minutes.
Stir in cheeses, Dijon, paprika, cayenne. Season with salt and pepper.
Fold in pasta and bacon. Transfer to 9×13 dish. Top with cheese.
Bake 20–25 minutes until golden and bubbling. Rest 5 minutes.
Garnish with parsley and serve hot.
