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!

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Why You’ll Love This Monterey Spaghetti
Taste Triumph: The blend of sharp Parmesan and mild Monterey Jack cheeses is so good. Combine those with garlic and a luxurious sour cream base, and you'll be amazed.
Packed with Nutrition: The spinach adds a layer of richness and texture without overpowering the dish. It’s healthy and delicious and won’t intimidate picky eaters.
Make-Ahead: You can assemble this dish up to 24 hours in advance. Then, simply bake it just before serving. It's easy, peasy, and delightfully cheesy!
Great for Leftovers: Many pasta dishes dry out when reheated. But this casserole maintains its creamy texture. It actually develops an even better taste the next day.
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
Follow these easy steps 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!

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.

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.















3 Comments
Can I use fresh spinach?
Is 8 oz of spaghetti correct? The recipe says it makes 8 servings but that does not seem like nearly enough spaghetti. I would like to make this but want to make sure this is correct. Thanks!
Hi, Natalie!
When I make this recipe, it’s typically only for 3-4 people, and we always have leftovers.
But… now that you mention it, I’m not sure there are enough leftovers to feed another 4-5 people.
This may actually be closer to 6 servings. Typically, 2 ounces of spaghetti is 1 serving. But in this case, of course, the other ingredients will add more “oomph.” Still, I think I’ll adjust this recipe. Six servings is probably more accurate.