Creamy Mushroom Spinach Penne Casserole

If you’re looking for a comforting, rich, and flavorful dinner that’s both satisfying and easy to prepare, this Creamy Mushroom Spinach Penne Casserole is exactly what you need. Combining tender penne pasta with sautéed mushrooms, fresh spinach, and a luscious creamy sauce, this dish is a delightful way to enjoy a vegetarian meal that feels indulgent and wholesome. Whether you’re cooking for a weeknight family dinner or a cozy weekend gathering, this casserole delivers on taste and texture every time.

Why This Recipe Is Reliable

This Creamy Mushroom Spinach Penne Casserole hits the mark because it balances simple ingredients with straightforward techniques. The olive oil gently sautés the onions, garlic, and mushrooms, bringing out their natural sweetness and earthiness. Adding fresh spinach boosts the nutritional value and adds vibrant color without overpowering the flavors. The heavy cream creates a velvety sauce that clings to every piece of pasta, while mozzarella and Parmesan cheeses melt and brown beautifully in the oven, giving you a golden, bubbly top layer. Italian seasoning rounds out the dish with a perfect herbal note.

The recipe is forgiving and flexible, allowing even beginner cooks to master it. Plus, the ingredients are pantry staples or easy to find fresh produce, making it a reliable go-to casserole for busy days.

The Ingredient Lineup

• 8 ounces penne pasta – Provides the perfect tubular shape to hold onto the creamy sauce.
• 2 tablespoons olive oil – For sautéing vegetables and adding a subtle fruity flavor.
• 1 small onion, diced – Adds sweetness and depth to the base.
• 3 garlic cloves, minced – Infuses the dish with aromatic richness.
• 8 ounces mushrooms, sliced – Earthy and meaty, the star vegetable in this casserole.
• 4 cups fresh spinach, chopped – Adds freshness and a boost of nutrients.
• 1 cup heavy cream – Creates a luscious, creamy sauce that binds everything together.
• 1 cup mozzarella cheese, shredded – Melts perfectly for gooey, cheesy goodness.
• 1/2 cup grated Parmesan cheese – Adds sharp, nutty flavor and helps with browning.
• 1 teaspoon Italian seasoning – A blend of herbs that enhances the overall flavor profile.
• Salt and pepper to taste – Essential for seasoning and bringing out the best in each ingredient.

Hardware & Gadgets

• Large pot – For boiling the penne pasta to al dente.
• Large skillet – For sautéing onions, garlic, mushrooms, and spinach.
• 9×9-inch baking dish – Perfect size for assembling and baking the casserole.
• Mixing spoon or spatula – To stir and combine ingredients smoothly.
• Measuring cups and spoons – For accuracy with liquids and seasonings.
• Grater – To shred mozzarella and grate Parmesan cheese fresh for better flavor.

Step-by-Step: Creamy Mushroom Spinach Penne Casserole

Step 1: Cook the Penne Pasta

Bring a large pot of salted water to a boil. Add 8 ounces of penne pasta and cook according to package instructions until al dente—usually about 10-12 minutes. Drain the pasta and set it aside. Don’t rinse it, as the starch helps the sauce cling better.

Step 2: Sauté Aromatics and Mushrooms

Heat 2 tablespoons of olive oil in a large skillet over medium heat. Add the diced onion and cook for 3-4 minutes until softened and translucent. Stir in the minced garlic and cook for another 1 minute until fragrant. Add the sliced mushrooms and sauté until they release their moisture and turn golden brown, about 6-8 minutes.

Step 3: Add Spinach and Seasonings

Once the mushrooms are tender, add 4 cups of chopped fresh spinach to the skillet. Stir until the spinach wilts down, which takes about 2-3 minutes. Sprinkle in 1 teaspoon of Italian seasoning, and season with salt and freshly cracked black pepper to taste.

Step 4: Make the Creamy Sauce

Pour 1 cup of heavy cream into the skillet with the vegetables. Stir and let it simmer gently for 2-3 minutes until the sauce slightly thickens. This creamy base will envelop the pasta beautifully.

Step 5: Combine Pasta and Sauce

Add the cooked penne pasta directly into the skillet with the creamy mushroom and spinach mixture. Stir well to ensure every piece of pasta is coated with the sauce.

Step 6: Assemble the Casserole

Preheat your oven to 375°F (190°C). Transfer the pasta mixture into a greased 9×9-inch baking dish. Evenly sprinkle 1 cup of shredded mozzarella cheese and 1/2 cup of grated Parmesan cheese on top.

Step 7: Bake Until Golden and Bubbling

Bake uncovered for 20-25 minutes, or until the cheese is melted, bubbly, and golden brown on top. Keep an eye on it near the end to avoid burning.

Step 8: Serve and Enjoy

Let the casserole cool for a few minutes before serving. This helps the sauce set slightly, making it easier to dish out. Enjoy your creamy, comforting creation!

Make It Year-Round

• Use frozen spinach when fresh isn’t available—just thaw and drain excess water before adding.
• Swap mushrooms for seasonal varieties like cremini, shiitake, or portobello for varied flavor.
• In the summer, add sun-dried tomatoes for a tangy twist.
• For a lighter version, substitute half-and-half or whole milk for heavy cream, though the sauce will be less rich.
• Try adding cooked chicken or turkey sausage to turn it into a hearty protein-packed meal, similar in spirit to a Cheesy Ground Turkey Pasta Casserole.

Problems & Prevention

• Soggy pasta: Avoid overcooking the penne; drain immediately when al dente.
• Watery casserole: Ensure sautéed mushrooms release and evaporate their moisture fully before adding cream.
• Uneven cooking: Spread the pasta evenly in the baking dish and don’t overload with sauce.
• Burnt cheese topping: Cover loosely with foil if cheese browns too quickly, removing foil the last 5 minutes.

Storage Pro Tips

This casserole stores beautifully and makes excellent leftovers. Place any uneaten portions in an airtight container and refrigerate for up to 3 days. To reheat, warm in the oven at 350°F (175°C) for 15-20 minutes or until heated through, which helps maintain the creamy texture and keeps the cheese melty. Avoid microwaving if possible, as it can make the pasta rubbery.

If you want to freeze it, assemble but do not bake. Wrap tightly and freeze for up to 2 months. When ready, thaw overnight in the fridge and bake as directed, adding a few extra minutes if needed.

Ask & Learn

Can I use a different type of pasta for this casserole?

Absolutely! While penne is ideal because the tubular shape holds sauce beautifully, you can use rigatoni, ziti, or even fusilli. If you want to try a close cousin, check out this Creamy Mushroom And Spinach Rigatoni for a similar flavor profile with rigatoni pasta.

Is there a way to make this casserole vegan?

Yes! Swap the heavy cream with coconut cream or a plant-based cream alternative, and use vegan mozzarella and Parmesan-style cheeses. Sauté the vegetables as usual, and you’ll still get a creamy, delicious dish.

How can I add protein without changing the recipe too much?

Add cooked chickpeas, white beans, or lentils for a vegetarian protein boost. Alternatively, stir in pre-cooked chicken or turkey sausage before baking, similar to the flavors in a Cheesy Ground Turkey Pasta Casserole.

Can I prepare this casserole ahead of time?

Yes! You can prepare the entire dish up to the baking step, cover it, and refrigerate for up to 24 hours before baking. This is a great way to save time on busy days. Just be sure to add a few extra minutes to the baking time if the casserole is cold from the fridge.

One Pan, More Ideas

• Try a cheesy, garlicky twist with the Creamy Garlic Parmesan Pasta Bake for a similar comforting baked pasta experience.
• For a heartier meat option, explore the Cheesy Ground Turkey Pasta Casserole that’s packed with protein and flavor.
• If you enjoy mushrooms and spinach, the Creamy Mushroom And Spinach Rigatoni offers a slightly different pasta shape but the same creamy, delicious vibe.

In Closing

This Creamy Mushroom Spinach Penne Casserole is a testament to how simple ingredients can come together to create a truly comforting and memorable meal. The combination of tender pasta, earthy mushrooms, vibrant spinach, and a rich, cheesy sauce makes every bite a delight. It’s versatile, easy to prepare, and sure to become a staple in your weekly dinner rotation. Whether you’re cooking for yourself, family, or friends, this casserole promises warmth and satisfaction in every serving. So, grab your skillet and baking dish, and get ready to enjoy a creamy, dreamy pasta experience!

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