Preheat oven to 350°F (177°C); lightly oil a 13X9 baking pan or grab a non-stick one.
Cook pasta per package directions and drain.
While pasta cooks, heat oil in a mediun skillet over medium-high heat; Cook kielbasa in skillet until browned on both sides, 5-7 min; drain.
In a large bowl, combine the pasta, kielbasa, spaghetti sauce, oregano, salt and pepper and mix well.
Pour into the baking pan; sprinkle with parsley and then the mozzarella.
Cover lightly with foil and bake in the preheated oven for 30-45 minutes until casserole is bubbly and the cheese is completely melted.
For OAMC: Prepare casserole but use a disposable (foil) baking pan; do NOT bake; double wrap casserole in plastic wrap, then in foil wrap and freeze; remove from freezer 24 hours or more in advance of need; remove wrapping and thaw in fridge; once thawed, preheat oven to 350°F (177°C); then cover lightly with foil and bake in the preheated oven for 30-45 minutes until casserole is bubbly and the cheese is completely melted.