Once the pasta is fully tender, carefully remove the foil. Sprinkle the reserved half cup of cheddar evenly over the top. Return the dish to the oven, uncovered, for 8 to 10 minutes until the cheese is fully melted and beginning to bubble and brown lightly at the edges. Remove from the oven and allow the casserole to rest for 10 minutes before serving — this resting time lets the sauce thicken slightly and makes the casserole easier to scoop in cohesive portions.
Toppings and Serving
This is where chili mac casserole truly comes into its own. All the toppings you would reach for on a bowl of chili translate directly: a generous spoonful of sour cream over each serving balances the richness and heat beautifully. Sliced jalapeños — fresh or pickled — add heat and brightness. Diced white or green onion adds crunch and sharpness. A handful of corn chips or Fritos crushed over the top provides texture contrast. Diced avocado or a spoonful of guacamole adds creaminess. A drizzle of hot sauce brings additional heat. Any or all of these toppings can go on the table alongside the casserole so each person customizes their own portion. Serve with a simple green salad and cornbread, which is the natural pairing for anything chili-adjacent.
Variations
For a spicier version, use hot canned chili, add a can of drained diced green chiles to the mixture, or stir in a teaspoon of cayenne or chipotle powder. For a richer, creamier result, substitute half a cup of the water with sour cream or cream cheese stirred into the warm chili mixture before pouring over the pasta. A layer of drained black beans spread over the macaroni before adding the chili adds protein and texture. For a smoky variation, add a half teaspoon of liquid smoke to the chili mixture. Pepper jack cheese in place of or alongside the cheddar adds heat and a slightly more complex flavor profile. For a crowd, double the recipe in a deeper baking dish and add 15 to 20 minutes to the covered baking time.
Storage
Leftovers keep well in an airtight container in the refrigerator for up to three days and reheat beautifully — add a splash of water or extra chili sauce to prevent the pasta from drying out. The casserole can be assembled completely, covered, and refrigerated up to 24 hours before baking — add 10 to 15 minutes to the covered baking time when starting from cold. It also freezes well after baking: cool completely, wrap tightly, and freeze for up to two months. Thaw overnight in the refrigerator and reheat covered in a 325°F oven until warmed through.
