Spaghetti Casserole Recipe

5 from 2 votes

This Spaghetti Casserole is tender pasta tossed in a hearty vegetarian mushroom sauce, then topped with cheese and baked to golden brown perfection. A comforting meal that’s perfect for feeding a crowd!

Prep Time15

Cook Time30

Total Time45

Course: Main Course

Cuisine: American, Italian

Diet: Vegetarian

Servings: servings

Author: Rena

Ingredients

16 ounces whole wheat spaghetti
1 tablespoon olive oil
2 pounds button mushrooms
1 teaspoon dried oregano
1 tablespoon smoked paprika
1 onion finely diced
3-4 garlic cloves minced
24 ounces marinara sauce
Kosher salt and pepper to taste
1 cup shredded mozzarella
1/2 cup grated parmesan cheese
chopped fresh parsley Optional, to garnish

Instructions

Preheat the oven to 375 F. Cook the 16 ounces whole wheat spaghetti according to package directions. Drain and set aside in a large baking dish.
Meanwhile, place half of the 2 pounds button mushrooms in a food processor and pulse a few times, just until small chopped. Repeat with the remaining mushrooms.
Heat the 1 tablespoon olive oil in a large deep pan over medium-high heat. Add the mushrooms and cook, stirring occasionally, for 8-10 minutes.
Once the mushrooms reduced their size to about half of the amount, stir in the 1 teaspoon dried oregano, 1 tablespoon smoked paprika, 1 onion (diced), and 3-4 garlic cloves (minced). Continue to cook for 5-6 minutes, stirring frequently.
Stir in the 24 ounces marinara sauce and simmer for a couple of minutes. Season the sauce with Kosher salt and pepper.
Pour the sauce over the cooked spaghetti and gently stir to combine; sprinkle with the 1 cup shredded mozzarella and 1/2 cup grated parmesan cheese. Bake the casserole for 25-30 minutes, or until bubbly and the cheese is melted.
Garnish with freshly chopped fresh parsley, if desired, and serve warm.

Video

Notes

Storing leftovers: Store in an airtight container in the refrigerator for 3 to 5 days. Reheat individual servings in the microwave or the entire pan, covered with foil, in the oven at 350ºF for about 20 to 30 minutes or until heated through.
Make ahead: You can prepare this dish up to 24 hours in advance. Cover and refrigerate until baking. An extra 5-10 minutes may need to be added to the bake time if it's cold from the fridge.
Freezing: If you plan to freeze this, I recommend undercooking the pasta a bit. Cover the pan with plastic wrap and then again with foil. Freeze for up to 3 months. When you’re ready to enjoy, thaw in the fridge, remove plastic wrap, and bake according to directions.

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