Go Back

Delicious Vegetarian Baked Spaghetti

Layers of protein-enriched spaghetti, vegetable-rich marinara sauce, and melted cheese baked until golden for a satisfying high-protein vegetarian dinner.
Print Recipe Pin Recipe
Prep Time 15 minutes
Cook Time 50 minutes
Total Time 1 hour 5 minutes
Servings: 6 servings
Course: Dinner, Main Course
Cuisine: American, Italian
Calories: 380
Ingredients Equipment Method Notes

Ingredients
  

  • 8 oz spaghetti use protein-enriched or whole wheat for extra protein
  • 2 tbsp olive oil
  • 1 medium onion diced
  • 1 bell pepper diced
  • 2 cups marinara sauce
  • 2 cups shredded mozzarella or Italian blend cheese
  • 1 cup sliced mushrooms or diced zucchini optional, for bulk
  • 1/4 tsp red pepper flakes optional
  • fresh parsley or basil for garnish

Equipment

  • 9x13-inch baking dish
  • Large pot for pasta
  • large skillet
  • colander
  • aluminum foil

Method
 

  1. Preheat oven to 375°F (190°C) and lightly grease a 9x13 inch baking dish with cooking spray or olive oil.
  2. Cook spaghetti in a large pot of salted water according to package instructions until al dente, about 8-10 minutes. Drain and set aside. Do not rinse.
  3. While pasta cooks, heat olive oil in a large skillet over medium heat. Add diced onions, bell peppers, and optional mushrooms or zucchini. Sauté for 5-8 minutes, stirring occasionally, until vegetables are tender and onions are translucent.
  4. Pour marinara sauce into the skillet with the vegetables. Stir well and simmer for 2-3 minutes until heated through. Add red pepper flakes if using.
  5. Spread a thin layer of the vegetable sauce across the bottom of the prepared baking dish.
  6. Layer half of the cooked spaghetti evenly over the sauce in the dish.
  7. Spoon half of the remaining vegetable sauce over the pasta layer, spreading to reach the edges. Sprinkle 1 cup of shredded cheese evenly over the sauce.
  8. Repeat layering with remaining spaghetti, spreading it over the cheese layer. Top with the rest of the sauce, spreading evenly.
  9. Sprinkle the final cup of cheese over the top, covering the entire surface.
  10. Cover the baking dish tightly with aluminum foil, tenting slightly if needed so foil doesn't touch the cheese.
  11. Bake covered for 25 minutes to heat through and meld flavors.
  12. Remove foil and bake for an additional 10-15 minutes, until cheese is melted, bubbly, and turning golden brown in spots.
  13. Let the casserole rest for 5-10 minutes before slicing and serving to allow layers to set. Garnish with fresh herbs.

Notes

Storage: Store leftovers in an airtight container in the refrigerator for up to 3 days. Flavors improve after a day as pasta absorbs more sauce.
Serving Suggestions: Serve with mixed green salad, garlic bread, steamed broccoli, or Caesar salad.
Substitutions: Boost protein by adding a layer of cottage cheese mixed with egg (like lasagna) or plant-based meat crumbles to the sauce. Use dairy-free cheese for vegan version. Different pasta shapes like penne or rigatoni work well.
Make Ahead: Assemble up to 24 hours in advance, cover tightly, and refrigerate. Add 10-15 minutes to covered baking time if baking cold. Freezes well for up to 3 months - assemble but don't bake, then bake from frozen adding 15-20 minutes to covered baking time.
Pro Tip: Cook pasta just until al dente as it continues to soften during baking. Don't rinse pasta - the starch helps sauce cling. Shred cheese from a block for better melting. If sauce seems thin, simmer to thicken before using.