I tweaked a recipe found online. You can add any toppings you like.
Rigatoni absorbs moisture aggressively during slow cooking, which dictates how this casserole behaves over time. Undercooking the pasta strictly to five minutes prevents the tubes from turning mushy while holding in the slow cooker for four hours. Starch molecules need that initial resistance so they do not disintegrate into the surrounding spaghetti sauce.
Assembling this dish entirely the night before is entirely viable. Pack the raw ingredients into the ceramic insert, cover tightly with plastic wrap, and refrigerate for up to twenty-four hours before plugging the base in. Cold inserts require an extra thirty minutes of total cooking time to reach the proper internal simmer.
Freezing works exceptionally well for baked pasta dishes containing ground beef and mozzarella. Wrap the cooled ceramic insert or individual portions in heavy-duty aluminum foil, then store them in the freezer for up to three months. Thaw frozen portions completely in the refrigerator for twenty-four hours before reheating to maintain structural integrity.
Reheating single portions requires trapped steam to prevent the rigatoni edges from hardening. Cover the dish loosely with foil and bake at 350 degrees Fahrenheit for twenty minutes, removing the cover for the final five minutes to re-crisp the top layer of pepperoni.