Instant Pot Cheesy Spaghetti Squash

As seen in: Plant-Based Meals Full of Flavor

This dish features spaghetti squash cooked quickly in an electric pressure cooker until tender. The squash strands are combined with spinach, creamy ricotta, and aromatic oregano, then filled back into the squash shells. A generous layer of marinara, mozzarella, and Parmesan is added before broiling briefly to achieve a melty, golden top. Garnished with fresh parsley, it offers a comforting and vibrant meal that’s perfect for a simple weeknight dinner or a crowd-pleasing side.

A woman named Sophie is smiling and holding a plate of food.
Created By Sophie
Last updated on Tue, 28 Oct 2025 23:16:28 GMT
A close up of a spaghetti squash with cheese and herbs. Save Pin
A close up of a spaghetti squash with cheese and herbs. | sophietable.com

This cheesy spaghetti squash recipe is a delightful way to enjoy a comforting meal that feels indulgent without being heavy. Using the Instant Pot, the squash cooks quickly and perfectly every time, saving you a ton of prep and wait time. I initially tried this dish when craving a lighter alternative to lasagna, and now it is a staple whenever I want something cheesy and satisfying in a flash.

I remember the first time I made this during a busy weeknight. It was ready faster than I could decide on takeout, and everyone loved the cheesy, melty topping on tender spaghetti squash strands.

Ingredients

  • Water: 1 cup to create steam for pressure cooking
  • Spaghetti squash: 1 medium, halved and seeds removed for tender, noodle-like strands
  • Kosher salt: to season and bring out the squash’s natural sweetness
  • Freshly ground black pepper: adds gentle heat and depth
  • Baby spinach: 2 cups for added freshness and nutrients
  • Ricotta: 1 1/2 cups contributes creamy texture and mild flavor
  • Dried oregano: 1 teaspoon for aromatic warmth
  • Crushed red pepper flakes: 1/4 teaspoon offers a subtle kick
  • Marinara: 1 1/2 cups brings acidity and rich tomato flavor to balance the cheese
  • Fresh mozzarella: 1/2 pound, thinly sliced to melt beautifully on top
  • Freshly grated Parmesan: 1/4 cup adds a salty, nutty finish
  • Freshly chopped parsley: for garnish and a burst of color

Step-by-Step Instructions

Place the Spaghetti Squash in the Instant Pot:
Put the metal trivet inside the Instant Pot and pour in 1 cup of water. Season the squash halves with kosher salt and freshly ground black pepper. Place the squash halves cut side up on the trivet. Lock the lid in place and set to pressure cook on High for 7 minutes. Use the quick release method according to your Instant Pot’s instructions. Carefully unlock and remove squash, letting it cool enough to handle.
Prepare the Cheesy Filling:
Preheat your oven to the broil setting to get ready for melting cheese. Using a fork, scrape the spaghetti squash flesh into a large bowl. Add the baby spinach, ricotta cheese, dried oregano, and crushed red pepper flakes. Toss everything to combine evenly, creating a creamy, flavorful mixture.
Assemble and Broil:
Spoon the spinach and ricotta mixture back into the empty squash skins. Spoon marinara sauce evenly on top. Arrange the thin slices of fresh mozzarella over the marinara, then sprinkle with freshly grated Parmesan. Place the stuffed squash halves on a baking sheet.
Melt and Garnish:
Place the baking sheet under the broiler and cook for about 5 minutes or until the cheese is bubbly and golden. Watch closely to avoid burning. Once melted, remove from the oven and garnish with freshly chopped parsley before serving.
A close up of a dish with spaghetti squash and cheese. Save Pin
A close up of a dish with spaghetti squash and cheese. | sophietable.com

The mozzarella is my favorite part because it melts perfectly over the tender spaghetti squash strands creating a luscious texture. A memorable moment with this dish was sharing it with family on a cozy evening when everyone wanted something warm and cheesy but still light enough to enjoy without leftovers lingering in the fridge.

Storage tips

Store any leftovers in an airtight container in the refrigerator for up to 3 days. Reheat gently in the oven or microwave to preserve the melty cheese texture. The squash strands may firm up when chilled so be sure to cover it well to keep moisture in.

Ingredient substitutions

Swap the ricotta for cottage cheese or a dollop of cream cheese for a different creamy base. Use shredded mozzarella if you don’t have fresh and add a little extra Parmesan to boost flavor. You can replace baby spinach with kale or swiss chard but cook it slightly before mixing in.

Serving suggestions

Serve with a crisp green salad dressed in lemon vinaigrette for balance. Garlic bread or rustic crusty bread are excellent accompaniments to mop up any extra marinara and cheesy filling. A light red wine or sparkling water with lemon pairs beautifully.

Cultural and Historical Context

A dish of spaghetti squash with cheese on top. Save Pin
A dish of spaghetti squash with cheese on top. | sophietable.com

Spaghetti squash is often used as a low-carb alternative to pasta and has gained popularity in many health-conscious kitchens. This recipe takes inspiration from Italian lasagna by layering cheeses and marinara sauce but uses squash strands to lighten the dish while keeping the comforting flavors of traditional baked pasta dishes.

Commonly Asked Questions

→ How do you know when the spaghetti squash is done cooking?

The spaghetti squash should be tender when pierced with a fork, and the strands should separate easily after cooking under pressure.

→ Can I prepare the squash without a pressure cooker?

Yes, baking the squash in the oven until tender is an alternative, but it will take considerably longer than using a pressure cooker.

→ What cheeses work best for this dish?

A combination of ricotta, mozzarella, and Parmesan delivers a creamy, melty, and flavorful topping that balances the squash’s delicate texture.

→ Can I add other vegetables inside the squash?

Absolutely, fresh spinach is lovely here, but mushrooms, bell peppers, or zucchini can also be sautéed and mixed in for added flavor.

→ How is the dish finished to get the cheese browned?

Broiling the stuffed squash for a few minutes melts and lightly browns the cheese, creating a rich and appetizing crust.

→ Is it important to remove the seeds before cooking?

Yes, removing the seeds creates space inside the squash and ensures even cooking throughout the strands.

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Instant Pot Cheesy Squash

Quickly cooked spaghetti squash with a cheesy, flavorful topping and fresh spinach melded inside.

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Preparation Time
10 Minutes
Cooking Duration
12 Minutes
Overall Time
22 Minutes
Created By: Sophie

Recipe Type: Vegetarian

Skill Level: Simple

Cuisine Type: Italian-American

Portion Size: 2 Number of Servings (2 stuffed spaghetti squash halves)

Diet Preferences: Low Carb, Vegetarian-Friendly, Free of Gluten

What You'll Need

→ Vegetables

01 1 medium spaghetti squash, halved and seeds removed
02 2 cups baby spinach

→ Liquids

03 240 ml water

→ Dairy

04 375 g ricotta cheese
05 225 g fresh mozzarella, thinly sliced
06 25 g freshly grated Parmesan cheese

→ Sauces and Seasonings

07 375 ml marinara sauce
08 1 tsp dried oregano
09 0.25 tsp crushed red pepper flakes
10 Kosher salt, to taste
11 Freshly ground black pepper, to taste

→ Garnish

12 Freshly chopped parsley

Step-by-Step Directions

Step 01

Place the trivet into the Instant Pot and pour in 240 ml of water. Season the spaghetti squash halves with kosher salt and freshly ground black pepper. Place the squash halves on the trivet, lock the lid, and set the Instant Pot to Pressure Cook on High for 7 minutes. Perform a quick release following the manufacturer's instructions. Remove the squash and allow to cool until manageable.

Step 02

Preheat the oven to broil. Use a fork to scrape the spaghetti squash strands into a large bowl, reserving the squash skins. Add the baby spinach, ricotta cheese, dried oregano, and crushed red pepper flakes. Toss to combine thoroughly. Spoon the mixture back into the reserved squash skins. Top with marinara sauce, sliced mozzarella, and grated Parmesan.

Step 03

Place the stuffed squash halves on a large baking sheet and broil in the oven until the cheese melts and bubbles, approximately 5 minutes. Remove from oven and garnish with freshly chopped parsley before serving.

Helpful Notes

  1. To prevent overcooking, strictly follow the Instant Pot manufacturer's quick release guidelines.

Recommended Tools

  • Instant Pot or comparable pressure cooker
  • Oven with broil function
  • Fork
  • Large mixing bowl
  • Baking sheet

Allergen Information

Always review ingredients for any allergens and consult a healthcare provider with any concerns.
  • Contains dairy products (ricotta, mozzarella, Parmesan)

Nutritional Information (Per Serving)

These details are estimates and shouldn't be considered professional health advice.
  • Calories: 450
  • Fat Content: 25 grams
  • Carbohydrate Content: 30 grams
  • Protein Content: 20 grams