Heat the oil in a large (12 inch) nonstick skillet over medium-high heat. Add the ground beef, onion, chili powder, cumin, cayenne and 1/2 t. salt. Cook, breaking up meat into small pieces, until it looses all the pink color, about 5 minutes. Add garlic and cook until fragrant, about 30 seconds or so.
Add brown sugar, tomato sauce, water and macaroni. Bring to a boil. Cover and cook, stirring often and adjusting the heat so that it maintains a lively simmer (somewhere between medium/medium-high heat), until the macaroni is tender, about 10 minutes or so. Season with salt & pepper if needed.
Off heat, stir in half the cheese. Sprinkle the remaining cheese on top.