1Preheat oven to 350^. Spray a 1 3/4 quart casserole dish.Set aside.
In a medium sauce pan heat the butter and oil add the onions and sugar and stir to cook the onion until the sugar melts and the onions begin to caramelize a little.Add salt and pepper to taste or a little Cayenne pepper. Stir in the flour and then quickly stir in the kahlua and cream, stir in the milk, stir as you make the sauce smooth.
2Stir in the cooked pasta and the shredded cheese.
Stir until cheese melts. Spoon mixture into casserole and place crumbled cracker crumbs on top.
Bake for 30 minutes- until it is heated through and bubbly.