Creamy Monterey Spaghetti Bake

Section: Satisfying Main Dishes for Every Occasion

This Monterey spaghetti bake combines tender spaghetti with a creamy, cheesy sauce made from sour cream, Parmesan, and Monterey Jack cheeses. Fresh garlic and frozen spinach add flavor and nutrition, while crispy French-fried onions provide a crunchy topping. The casserole is easy to prepare, can be made ahead, and reheats well without drying out. Perfect for a comforting, crowd-pleasing dinner with rich textures and balanced flavors.

A woman wearing a chef's hat and apron.
Recipe Author Maria
Updated as of Mon, 23 Jun 2025 16:05:52 GMT
A close up of a spaghetti dish with cheese and spinach. Bookmark
A close up of a spaghetti dish with cheese and spinach. | foodbymary.com

This Monterey spaghetti bake is the ultimate pasta recipe! Once you try this crowd-pleasing dinner, you’ll understand why it’s a family favorite.

It’s creamy, cheesy, and packed with little surprises like spinach and crispy French-fried onions. Each bite is better than the last.

It’s a delicious, easy casserole that effortlessly balances rich flavors and satisfying textures.

Don’t be ashamed if you come back for thirds!

Ingredients

  • Spaghetti Noodles: The hearty, satisfying base of the casserole. It holds the creamy, cheesy mixture together.
  • Eggs: They help bind the ingredients for a rich, cohesive texture throughout the dish.
  • Sour Cream: It adds creaminess and a tangy flavor. It also balances the richness of the cheeses.
  • Parmesan Cheese: It offers a savory, nutty taste that enhances the overall depth of flavor.
  • Garlic: It infuses the dish with a subtle yet aromatic punch of flavor. Avoid garlic powder; stick to freshly minced instead.
  • Shredded Monterey Jack Cheese: It melts beautifully into the casserole for a mild, creamy, and slightly sweet cheesiness.
  • Frozen Chopped Spinach: It provides a pop of color, nutrients, and earthy flavor. It complements the richness of the cheese quite nicely, as well. If using fresh spinach, you’ll need about 16 ounces of raw spinach to make 10 ounces of cooked.
  • French-Fried Onions: Crispy fried onions are the crunchy, savory topping. They add texture and a burst of flavor to every bite.

How to Make Monterey Spaghetti

1. PREPARE.
Preheat the oven to 350 degrees Fahrenheit. Grease a 9×13-inch baking dish. Set aside.
2. COOK SPAGHETTI.
Cook it in a large pot of salted, boiling water. Cook according to the package directions until al dente, then drain and set aside.
3. MIX BASE.
Whisk the eggs in a large bowl until smooth. Then, stir in the sour cream, Parmesan cheese, and minced garlic.
4. COMBINE.
Add the slightly cooled cooked spaghetti to the egg mixture and toss to coat. Fold in the shredded Monterey Jack, chopped spinach, and one of the cans of French onions. Mix well.
5. ASSEMBLE.
Spread the mixture evenly into the baking dish and cover with aluminum foil.
6. BAKE.
Bake, covered, for 30 minutes. Then, uncover and sprinkle the remaining onions on top. Bake for another 5 minutes, uncovered, until the crispy fried onions are crisp and golden brown.
7. SERVE.
Remove the casserole from the oven and let it rest for a few minutes. Then, enjoy!
A bowl of Monterey Spaghetti. Bookmark
A bowl of Monterey Spaghetti. | foodbymary.com

Tips for the Best Monterey Spaghetti

These tips and tricks will make your spaghetti sensational.

Don’t overcook the pasta! Boil it until it’s just tender, then drain it immediately. It’ll keep cooking in the oven, so you don’t want to fully cook it initially.

Don’t get scrambled. Don’t add the hot pasta to the egg mixture, or it could scramble the eggs. Instead, set it aside to let it cool slightly first.

Ditch the excess liquid. Squeeze as much liquid as possible from the thawed spinach using a kitchen towel. Excess moisture can make the casserole watery.

Skip the bagged stuff. Pre-shredded cheeses aren’t the way to go. They often contain anti-caking agents that can negatively affect the casserole’s texture. Shred the Monterey Jack and grate the Parmesan cheese yourself.

Boost the flavor. Lightly saute the minced garlic for 1 to 2 minutes before mixing it in. Doing so will give the spaghetti bake a deeper, sweeter garlic flavor. For a bit of heat, stir in a pinch of crushed red pepper flakes or diced jalapeno.

Experiment and have fun. Try replacing some of the Monterey Jack cheese with mozzarella for stretchiness. (Or sharp cheddar for a tangier flavor.) You can also swap out frozen spinach for fresh spinach or other greens. (i.e., kale, Swiss chard, or broccoli.) Add-ins like shredded chicken, sun-dried tomatoes, or bacon work well, too.

A fork is being used to scoop spaghetti with broccoli and cheese. Bookmark
A fork is being used to scoop spaghetti with broccoli and cheese. | foodbymary.com

How to Store

Monterey spaghetti stores well, but you can’t freeze it. The texture won’t hold up once it thaws.

To Store: Let the leftovers cool completely. Then, refrigerate them in an airtight container for up to 4 days.

To Reheat: Reheat desired portions covered in the oven. (350 degrees/15-20 minutes) Or microwave on high for 1 to 2 minutes. Add a sprinkle of fresh cheese on top for extra melty goodness. If the mixture seems dry, add a splash of chicken broth.

Frequently Asked Questions

→ Can I use fresh spinach instead of frozen?

Yes, substitute about 16 ounces of fresh raw spinach for 10 ounces of frozen cooked spinach. Be sure to wilt and drain excess moisture before mixing.

→ How do I prevent the eggs from scrambling?

Allow cooked spaghetti to cool slightly before mixing with the egg and sour cream base. This avoids overheating the eggs and keeps the texture smooth.

→ What is the best way to store leftovers?

Cool leftovers completely, then refrigerate in an airtight container for up to 4 days. Reheat covered in the oven or microwave with a splash of broth if dry.

→ Can I freeze the casserole?

Freezing is not recommended as the texture may become watery and change upon thawing.

→ How can I enhance the garlic flavor?

Lightly sauté minced garlic for 1-2 minutes before mixing into the base for a sweeter, deeper garlic aroma.

→ Are there any good add-ins to vary the dish?

Try adding shredded chicken, sun-dried tomatoes, bacon, or swap some Monterey Jack for mozzarella or sharp cheddar for different flavor profiles.

Monterey Spaghetti Bake

Creamy spaghetti bake with Monterey Jack, spinach, and crispy fried onions in a cheesy, satisfying casserole.

Prep Time
20 minutes
Cooking Time
35 minutes
Overall Time
55 minutes
Recipe Author: Maria

Dish Category: Main Dishes

Recipe Difficulty: Beginner-Friendly

Cuisine: American

Serves: 6 Serving Size (6 servings)

Dietary Options: Vegetarian

What You’ll Need to Cook

→ Pasta

Ingredient 01 8 ounces spaghetti noodles

→ Binding and Creaminess

Ingredient 02 3 large eggs
Ingredient 03 1 cup sour cream

→ Cheeses

Ingredient 04 1 cup freshly grated Parmesan cheese
Ingredient 05 2 cups shredded Monterey Jack cheese

→ Vegetables

Ingredient 06 10 ounces frozen chopped spinach, thawed and drained

→ Aromatics and Toppings

Ingredient 07 2 cloves fresh garlic, minced
Ingredient 08 1 can French-fried onions, divided

Steps to Prepare

Step 01

Preheat oven to 350°F (175°C). Grease a 9×13-inch baking dish and set aside.

Step 02

Cook spaghetti in a large pot of salted boiling water until al dente according to package instructions. Drain and let cool slightly.

Step 03

In a large bowl, whisk eggs until smooth. Stir in sour cream, grated Parmesan, and minced garlic.

Step 04

Add cooled spaghetti to the egg mixture and toss to coat. Fold in shredded Monterey Jack cheese, thawed spinach (excess moisture squeezed out), and half of the French-fried onions. Mix thoroughly.

Step 05

Spread the mixture evenly into the prepared baking dish and cover with aluminum foil.

Step 06

Bake covered for 30 minutes in the preheated oven.

Step 07

Remove foil, sprinkle remaining French-fried onions over the top, and bake uncovered for an additional 5 minutes until onions are golden and crisp.

Step 08

Remove casserole from oven and let rest a few minutes before serving.

Extra Cooking Tips

  1. Avoid overcooking pasta; it will continue cooking in the oven. Let cooked spaghetti cool before mixing with eggs to prevent scrambling. Squeeze excess moisture from spinach to avoid watery casserole.
  2. Lightly sauté minced garlic for 1-2 minutes before mixing in to deepen flavor. Freshly shred cheeses for best texture and taste.

Must-Have Tools

  • 9×13-inch baking dish
  • Large pot
  • Mixing bowls
  • Whisk

Allergen Information

Always check ingredient labels for allergens and seek expert advice if uncertain.
  • Contains dairy and eggs; not suitable for those with dairy or egg allergies.
  • Contains gluten due to spaghetti noodles.

Nutrition Info (Per Serving)

These details are for guidance and aren’t a replacement for professional advice.
  • Calories Count: 420
  • Fats: 18.2 grams
  • Carbs: 45.5 grams
  • Proteins: 17 grams