My brother survived college on this genius budget friendly pizza pasta hybrid. Using only 4 ingredients makes a bubbling cheesy meal that completely satisfies any cravings.

Cover again and cook on LOW for another 15–25 minutes, or until the cheese on top is fully melted, gooey, and starting to bubble around the edges. If your slow cooker lid collects a lot of condensation, carefully lift it and wipe off the moisture with a clean towel once during this time before setting it back on, so the top stays cheesy instead of watery.
For a college-dorm-style meal prep or easy weeknight grab-and-go portions, turn off the slow cooker and let the pasta sit uncovered for about 5–10 minutes to thicken slightly. Then, carefully spoon the hot pepperoni macaroni into two disposable foil trays, spreading it into even layers so the top stays covered in melted cheese and pepperoni slices. Serve hot right away, or cool slightly before covering the trays with foil for transport or storage.
Refrigerate any leftovers in an airtight container (or covered foil trays) once cooled to room temperature, and eat within 3–4 days. Reheat individual portions in the microwave until steaming hot, adding a spoonful of extra sauce or a splash of water if it seems dry, and top with extra cheese if you like.
Variations & Tips
To keep this a true 4-ingredient recipe, any tweaks should swap one of the main ingredients rather than add a bunch more. You can use any short pasta you have on hand—shells, rotini, or penne all work similarly to elbow macaroni, though thicker shapes may take a little longer to soften. If you prefer a slightly lighter dish, choose turkey pepperoni instead of regular. For a spicier version, use a zesty or arrabbiata-style pizza or pasta sauce in place of plain marinara. If you want a cheesier, stretchier top without changing the ingredient count, simply shift more of the mozzarella to the top layer and slightly reduce what you mix in at the beginning. For extra crispy pepperoni edges, you can transfer the cooked pasta to an oven-safe dish or foil tray and broil for 2–3 minutes, watching closely. Food safety tips: Always cook the pasta mixture until it is piping hot and the internal temperature reaches at least 165°F before serving. Do not leave the cooked pasta sitting at room temperature for more than 2 hours (or 1 hour if your kitchen is very warm); refrigerate leftovers promptly. Reheat leftovers until steaming hot all the way through, and discard any portions that have been left out too long or show signs of spoilage, such as off smells or mold.