In medium saucepan, simmer chili until heated through.
Cook macaroni according to package directions; drain well and set aside.
Grease a deep 8-quart or similar casserole dish.
Spoon 1 cup of chili evenly on bottom of dish. Next, layer half of the macaroni, drizzle half of the ketchup (approx. 1/4 cup), half of the remaining chili and half of the cheeses. Repeat layering with remaining macaroni, 1/4 cup ketchup, remainder of chili and remaining cheeses. Top with jalapeno slices, if desired.
Cover and bake 30 minutes. Remove cover and bake an additional 10 minutes or until heated through and cheese is bubbly.
*NOTE: I prefer my home-made chili in this recipe, but if I use canned chili, I like to add chopped green pepper, chopped onion, 4 oz. can green chilies, cayenne pepper or whatever I have on hand to "doctor" it up.