Bring a large pot of water to a boil. Salt it and cook pasta to al dente. Drain and reserve. Preheat broiler.
Melt butter in a medium saucepot over medium heat. Whisk in flour, cook for 1 minute, then raise heat a bit and add beer. Reduce until almost evaporated then whisk in honey or syrup and milk. Season with cloves or allspice, mustard, cayenne, a little freshly grated nutmeg, some salt and pepper. Thicken to coat spoon, a couple of minutes, then taste to adjust seasonings.
Whisk in pumpkin pure then stir in about 2 cups grated cheese with a wooden spoon until melted. Combine pasta with sauce and arrange in a casserole or individual ramekins. Sprinkle remaining cheese and a light dusting of paprika. Broil to brown and bubble. Garnish with chopped parsley or chives.