These Mushroom Spinach Egg Muffins are an easy make-ahead breakfast filled with savory mushrooms, tender spinach, fluffy eggs, and melted mozzarella. Cooking the vegetables first keeps excess moisture out of the muffins, while a splash of milk helps the eggs stay tender. Bake a batch once, refrigerate the extras, and reheat them for busy mornings.
Table of Contents
Table of Contents
Why These Make-Ahead Egg Muffins Work
- Meal-prep friendly: One batch makes 12 individual muffins that are easy to portion and reheat.
- No watery centers: Sautéing the mushrooms and spinach first removes excess moisture before baking.
- Simple savory flavor: Mozzarella, garlic, mushrooms, and black pepper keep the filling flavorful without making it heavy.
- Easy to grab: Two muffins make a convenient breakfast portion for mornings when time is short.
Simple Ingredients for Mushroom Spinach Egg Muffins
- Large eggs: The main structure of the muffins and the base of the filling.
- Cremini mushrooms: Add deep savory flavor; cook them until their released liquid has evaporated.
- Baby spinach: Wilts quickly and adds color without needing much prep.
- Yellow onion: Gives the vegetable mixture a mild sweet-savory base.
- Part-skim mozzarella: Melts smoothly through the eggs without overpowering the mushrooms.
- 2% milk: Loosens the egg mixture slightly for a softer texture.
- Olive oil: Helps brown the mushrooms and soften the onion.
- Garlic powder, salt, and black pepper: Season the egg mixture evenly from the inside out.
- Nonstick cooking spray: Helps the baked egg muffins release cleanly from the pan.
How to Make Mushroom Spinach Egg Muffins
Step 1: Prep the Pan and Oven
Heat the oven to 375°F. Generously coat a standard 12-cup muffin pan with nonstick cooking spray so the egg muffins release cleanly after baking.
Step 2: Brown the Mushrooms and Onion
Heat the olive oil in a large skillet over medium-high heat. Add the mushrooms and onion and cook for 6 to 8 minutes, stirring occasionally, until the mushrooms are browned and most of their released liquid has evaporated.
Step 3: Wilt the Spinach
Add the baby spinach and cook for 1 to 2 minutes, just until wilted. Remove the skillet from the heat and let the vegetables cool for about 5 minutes so they do not begin cooking the eggs when mixed.
Step 4: Mix and Fill
Whisk the eggs, milk, garlic powder, salt, and black pepper in a large bowl until evenly combined. Stir in the cooled vegetables and mozzarella, then divide the mixture evenly among the 12 muffin cups, filling each about three-quarters full.
Step 5: Bake Until Just Set
Bake for 18 to 22 minutes, until the tops are puffed, the centers no longer jiggle, and the egg mixture reaches 160°F in the center. Cool in the pan for 5 minutes, then loosen the edges with a thin spatula or butter knife and lift the muffins out.
Mushroom Spinach Egg Muffins
Ingredients
- Nonstick cooking spray for the muffin pan
- 1 tablespoon olive oil
- 8 ounces cremini mushrooms finely chopped
- 1/4 cup finely diced yellow onion
- 2 packed cups baby spinach roughly chopped
- 12 large eggs
- 1/4 cup 2% milk
- 1/2 cup shredded part-skim mozzarella cheese
- 1/2 teaspoon garlic powder
- 1/2 teaspoon fine sea salt
- 1/4 teaspoon ground black pepper
Instructions
- Preheat the oven to 375°F. Generously coat a standard 12-cup muffin pan with nonstick cooking spray.
- Heat 1 tablespoon olive oil in a large skillet over medium-high heat. Add the finely chopped mushrooms and diced onion. Cook for 6 to 8 minutes, stirring occasionally, until the mushrooms are browned, the onion is softened, and most of the mushroom liquid has evaporated.
- Add the chopped baby spinach to the skillet. Cook for 1 to 2 minutes, stirring, until just wilted. Remove the skillet from the heat and let the vegetable mixture cool for about 5 minutes.
- In a large mixing bowl, whisk together the eggs, milk, garlic powder, fine sea salt, and black pepper until evenly combined.
- Stir the cooled mushroom-spinach mixture and shredded mozzarella into the eggs until evenly distributed.
- Divide the mixture evenly among the 12 prepared muffin cups, filling each cup about three-quarters full.
- Bake at 375°F for 18 to 22 minutes. The muffins are ready when the tops are puffed, the centers no longer jiggle, and the center of an egg muffin reaches 160°F.
- Let the muffins cool in the pan for 5 minutes. Run a thin spatula or butter knife around the edges as needed, then carefully remove the muffins from the pan.
Notes
- Finely chopping the mushrooms helps distribute them evenly through the muffins.
- Cook the mushrooms until most of their released moisture has evaporated to prevent watery egg muffins.
- Avoid overbaking. Remove the muffins once the centers are fully set.
- Refrigerate cooled muffins in an airtight container for 3 to 4 days.
- Freeze cooled muffins in a freezer-safe container or bag for up to 2 months for best texture.
- Microwave refrigerated muffins for about 30 to 60 seconds, or until hot throughout.
- Frozen muffins can be thawed overnight in the refrigerator before reheating.
- Nutrition is an estimate and may vary depending on ingredient brands.
Nutrition
Keep the Egg Muffins Tender, Not Rubbery
- Cook off the mushroom liquid: Wet vegetables can make the muffins spongy or watery.
- Cool the filling briefly: Adding very hot vegetables directly to the eggs can create uneven cooking.
- Do not overbake: Pull the muffins once the centers are set; extra oven time makes eggs firm and rubbery.
- Grease the pan well: Egg sticks easily to metal muffin cups, especially around the cheese.
- Let them rest for 5 minutes: The muffins firm slightly as they cool and release more cleanly.
Store, Freeze & Reheat for Busy Mornings
Cool the muffins, then refrigerate them in an airtight container for 3 to 4 days. For longer storage, freeze the cooled muffins in a freezer-safe container or bag for up to 2 months for best texture. Reheat refrigerated muffins in the microwave for about 30 to 60 seconds, or until hot throughout. Frozen muffins can be thawed overnight first or reheated in short intervals until fully heated.
Mushroom Spinach Egg Muffins FAQ
Can I Use Frozen Spinach?
Yes. Thaw it completely and squeeze out as much water as possible before adding it. About 1/2 cup thawed, well-drained spinach is a practical substitute for the fresh spinach in this recipe.
Can I Make These Without Cheese?
Yes. The muffins will still set without mozzarella, though the texture will be slightly less rich and the flavor milder. No other adjustment is needed.
Why Did My Egg Muffins Deflate?
A little deflation is normal because eggs puff from steam in the oven and settle as they cool. For the best shape, avoid over-whisking the eggs and do not overbake the muffins.