Low Carb Loaded Zucchini Casserole – Comforting, Flavor-Packed, and Weeknight Easy

This Low Carb Loaded Zucchini Casserole is the cozy, cheesy bake you crave on a busy weeknight. It’s packed with tender zucchini, crispy bacon, melted cheese, and a creamy, savory sauce that brings everything together. Even non–low carb eaters love it, and leftovers taste just as good the next day.

It’s simple to assemble, easy to customize, and feels like comfort food without the carb-heavy crash.

Low Carb Loaded Zucchini Casserole - Comforting, Flavor-Packed, and Weeknight Easy

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Prep Time 15 minutes mins

Cook Time 30 minutes mins

Total Time 45 minutes mins

Servings 4 servings

Ingredients

  

• 4 medium zucchini (about 2 pounds), sliced into 1/4-inch rounds
• 1 teaspoon kosher salt (for drawing out moisture) + more to taste
• 1 tablespoon olive oil or avocado oil
• 1 small yellow onion, finely chopped
• 3 cloves garlic, minced
• 6 slices bacon, cooked crisp and crumbled (reserve 1 tablespoon bacon fat, optional)
• 1 cup shredded sharp cheddar cheese
• 1/2 cup shredded mozzarella cheese
• 1/4 cup grated Parmesan cheese
• 3 large eggs
• 1/2 cup sour cream (or full-fat Greek yogurt)
• 1/4 cup heavy cream
• 1 teaspoon Dijon mustard
• 1/2 teaspoon black pepper
• 1/2 teaspoon smoked paprika (optional)
• 2 tablespoons chopped fresh chives or green onions
• 2 tablespoons chopped fresh parsley (optional, for garnish)

Instructions

 

• Prep the zucchini: Slice the zucchini into 1/4-inch rounds. Place in a large colander and toss with 1 teaspoon kosher salt. Let sit for 20 minutes to draw out excess moisture. Pat dry thoroughly with paper towels.
• Cook the bacon: In a skillet, cook bacon until crisp. Drain on paper towels and crumble. If you like, reserve 1 tablespoon bacon fat for sautéing the aromatics.
• Sauté onion and garlic: In the same skillet, heat oil (or bacon fat) over medium heat. Add onion and cook 3–4 minutes until softened. Stir in garlic for 30 seconds until fragrant. Remove from heat.
• Pre-bake the zucchini: Preheat oven to 400°F (200°C). Spread zucchini rounds on two parchment-lined baking sheets. Bake for 10–12 minutes, flipping once, until just tender and releasing moisture. Pat again with paper towels if needed. Reduce oven to 375°F (190°C).
• Mix the creamy base: In a bowl, whisk eggs, sour cream, and heavy cream. Add Dijon, black pepper, smoked paprika, and a pinch of salt. Stir in the sautéed onion and garlic.
• Assemble the casserole: Lightly grease a 9x13-inch baking dish. Layer half the zucchini, then half the cheddar and mozzarella, and half the bacon. Pour over half the creamy mixture. Repeat with remaining zucchini, cheeses, and bacon. Sprinkle Parmesan on top and finish with chives or green onions.
• Bake: Bake at 375°F (190°C) for 22–28 minutes, until the top is golden and the center is set. If you want extra browning, broil for 1–2 minutes at the end, watching closely.
• Rest and serve: Let the casserole rest for 10 minutes to set. Garnish with parsley if using. Slice and serve warm.

Why This Recipe Works

• Moisture management: Zucchini releases a lot of water. Salting and pre-baking keeps the casserole rich and creamy, not watery.
• Layered flavor: Garlic, onions, bacon, and two cheeses create depth without complicated steps.
• Protein plus fat: Eggs, bacon, and cheese make it satisfying and filling while keeping carbs low.
• Make-ahead friendly: You can prep components in advance, then assemble and bake when you’re ready.
• Kid-approved texture: The golden top and tender zucchini slices deliver a comfort-food feel with a lighter base.

Ingredients

• 4 medium zucchini (about 2 pounds), sliced into 1/4-inch rounds
• 1 teaspoon kosher salt (for drawing out moisture) + more to taste
• 1 tablespoon olive oil or avocado oil
• 1 small yellow onion, finely chopped
• 3 cloves garlic, minced
• 6 slices bacon, cooked crisp and crumbled (reserve 1 tablespoon bacon fat, optional)
• 1 cup shredded sharp cheddar cheese
• 1/2 cup shredded mozzarella cheese
• 1/4 cup grated Parmesan cheese
• 3 large eggs
• 1/2 cup sour cream (or full-fat Greek yogurt)
• 1/4 cup heavy cream
• 1 teaspoon Dijon mustard
• 1/2 teaspoon black pepper
• 1/2 teaspoon smoked paprika (optional)
• 2 tablespoons chopped fresh chives or green onions
• 2 tablespoons chopped fresh parsley (optional, for garnish)

Step-by-Step Instructions

1. Prep the zucchini: Slice the zucchini into 1/4-inch rounds. Place in a large colander and toss with 1 teaspoon kosher salt.

   Let sit for 20 minutes to draw out excess moisture. Pat dry thoroughly with paper towels.

2. Cook the bacon: In a skillet, cook bacon until crisp. Drain on paper towels and crumble.

   If you like, reserve 1 tablespoon bacon fat for sautéing the aromatics.

3. Sauté onion and garlic: In the same skillet, heat oil (or bacon fat) over medium heat. Add onion and cook 3–4 minutes until softened. Stir in garlic for 30 seconds until fragrant.

   Remove from heat.

4. Pre-bake the zucchini: Preheat oven to 400°F (200°C). Spread zucchini rounds on two parchment-lined baking sheets. Bake for 10–12 minutes, flipping once, until just tender and releasing moisture.

   Pat again with paper towels if needed. Reduce oven to 375°F (190°C).

5. Mix the creamy base: In a bowl, whisk eggs, sour cream, and heavy cream. Add Dijon, black pepper, smoked paprika, and a pinch of salt.

   Stir in the sautéed onion and garlic.

6. Assemble the casserole: Lightly grease a 9×13-inch baking dish. Layer half the zucchini, then half the cheddar and mozzarella, and half the bacon. Pour over half the creamy mixture.

   Repeat with remaining zucchini, cheeses, and bacon. Sprinkle Parmesan on top and finish with chives or green onions.

7. Bake: Bake at 375°F (190°C) for 22–28 minutes, until the top is golden and the center is set. If you want extra browning, broil for 1–2 minutes at the end, watching closely.
8. Rest and serve: Let the casserole rest for 10 minutes to set.

   Garnish with parsley if using. Slice and serve warm.

Storage Instructions

• Refrigerator: Cool completely, then store in an airtight container for 3–4 days.
• Freezer: Freeze individual portions tightly wrapped for up to 2 months. Thaw in the fridge overnight.
• Reheating: Reheat in a 350°F (175°C) oven for 12–15 minutes, or microwave in 30-second bursts.

  For best texture, oven reheating is preferred.

Health Benefits

• Low in carbs, high in nutrients: Zucchini provides fiber, vitamin C, and potassium while keeping net carbs low.
• Satiating combo: The blend of protein and fat from eggs, cheese, and bacon helps control hunger and supports steady energy.
• Gluten-free friendly: There are no breadcrumbs or flour. It’s naturally gluten-free when all ingredients are verified.
• Vegetable-forward: Each serving includes a generous portion of zucchini, making it a great way to increase veggie intake.

Pitfalls to Watch Out For

• Watery casserole: Skipping the salting and pre-baking steps can leave excess moisture. Dry the zucchini well for the best texture.
• Overbaking: Too long in the oven can make the eggs rubbery.

  Bake until set but still tender.

• Underseasoning: Zucchini is mild. Taste the creamy mixture and adjust salt and pepper before assembling.
• Cheese overload on top: Too thick a cheese cap can trap moisture. Balance cheese throughout the layers.

Variations You Can Try

• Southwest style: Add chopped green chiles, cumin, and pepper jack cheese.

  Top with cilantro and a dollop of salsa.

• Chicken bacon ranch: Stir in 1–2 cups cooked shredded chicken and 1 tablespoon ranch seasoning. Use mozzarella and cheddar.
• Veggie-packed: Add sautéed mushrooms, bell peppers, or spinach. Cook off moisture first to keep the dish from getting watery.
• Italian-inspired: Use Italian sausage instead of bacon, add a pinch of red pepper flakes and Italian seasoning, and swap mozzarella for provolone.
• Dairy-light: Use cottage cheese blended smooth with eggs instead of sour cream and heavy cream.

  Choose a lighter hand with cheese.

• Keto boost: Add a bit more bacon and Parmesan and finish with a drizzle of garlic butter for extra fat and flavor.

FAQ

Can I skip the pre-baking step?

Pre-baking helps release water and keeps the casserole from turning soggy. You can skip it in a pinch, but expect more liquid. If you do, salt and drain the zucchini longer and blot aggressively.

What’s the best cheese combo?

A blend of sharp cheddar for flavor, mozzarella for melt, and Parmesan for umami gives a great balance.

You can swap in Gruyère, provolone, or Monterey Jack if that’s what you have.

Can I make it vegetarian?

Yes. Omit the bacon and add sautéed mushrooms or sun-dried tomatoes for a savory punch. A dash of liquid smoke or smoked paprika keeps the “loaded” vibe.

How do I keep leftovers from getting watery?

Cool completely before refrigerating so condensation doesn’t build up.

Reheat in the oven to evaporate excess moisture and re-crisp the top.

Can I use yellow squash instead of zucchini?

Absolutely. Yellow squash behaves similarly. You can also mix the two for a colorful casserole.

Is this meal prep friendly?

Very.

Assemble up to one day ahead, cover, and refrigerate. Add 5–10 extra minutes to the baking time if going straight from the fridge.

What size pan should I use?

A 9×13-inch dish works best for even layers and a good ratio of sauce to veggies. An 8×11-inch pan also works; baking time may vary slightly.

How can I add more protein?

Stir in cooked chicken, turkey sausage, or ground beef.

Keep seasonings balanced and pre-cook thoroughly to avoid extra moisture.

What if I don’t have sour cream?

Full-fat Greek yogurt is a great swap. It adds tang and creaminess with similar thickness.

Can I make it spicier?

Yes. Add red pepper flakes, a diced jalapeño, or a dash of hot sauce to the egg mixture.

Pepper jack cheese also adds a gentle kick.

Final Thoughts

This Low Carb Loaded Zucchini Casserole delivers all the cozy, cheesy satisfaction of a classic bake without the heaviness. With smart moisture control and a simple creamy base, it turns basic ingredients into something special. Keep it as-is for a weeknight staple, or try a variation to match your mood.

Either way, it’s a reliable, flavorful dish you’ll want in your regular rotation.