One-Pot Breakfast Casserole Muffins

Featured in: Warm Bakes

These savory breakfast muffins combine eggs, cheese, and a medley of fresh vegetables in a single dish. Prepared in a muffin tin, they bake to a golden finish that’s perfect for quick, on-the-go meals. Customizable with cooked bacon or sausage, or separated for vegetarian options, these muffins store well refrigerated or frozen. They provide a flavorful, protein-packed start to the day, ideal for meal prep and easy serving warm or cold.

Updated on Wed, 19 Nov 2025 16:58:00 GMT
Golden brown One-Pot Breakfast Casserole Muffins filled with savory cheese, vegetables, and optional sausage. Save
Golden brown One-Pot Breakfast Casserole Muffins filled with savory cheese, vegetables, and optional sausage. | butterhollow.com

Savory, portable breakfast muffins packed with eggs, cheese, and veggies are a delicious way to start your morning. These casserole muffins are perfect for meal prep, budget-friendly, and taste delicious hot or cold.

I began making these for busy school mornings. They quickly became a favorite in my house because they can be made ahead and everyone can grab one on the run.

Ingredients

  • Base: 8 large eggs, 1/3 cup whole milk (or dairy-free alternative)
  • Vegetables: 1 cup baby spinach, chopped, 1/2 cup red bell pepper, diced, 1/2 cup onion, finely chopped
  • Protein (optional): 3/4 cup cooked bacon or breakfast sausage, crumbled (omit for vegetarian)
  • Cheese: 1 cup shredded cheddar cheese (or Monterey Jack)
  • Seasonings: 1/2 teaspoon salt, 1/4 teaspoon black pepper, 1/4 teaspoon smoked paprika
  • Oils: 1 tablespoon olive oil or nonstick spray (for greasing muffin tin)

Instructions

Preheat & Prep:
Preheat oven to 350°F (175°C). Grease a 12-cup muffin tin with olive oil or nonstick spray.
Mix Base:
In a large bowl, whisk together eggs and milk until fully combined.
Add Fillings:
Stir in spinach, bell pepper, onion, cooked bacon or sausage (if using), cheese, salt, black pepper, and smoked paprika.
Fill Muffin Tin:
Divide the mixture evenly among the 12 muffin cups, filling each about 3/4 full.
Bake:
Bake for 22–25 minutes, or until muffins are set and lightly golden.
Cool & Remove:
Cool in the tin for 5 minutes, then run a knife around the edges and remove muffins. Serve warm or allow to cool completely for storage.
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| butterhollow.com

Our family loves packing these in lunchboxes or bringing them on weekend trips. They disappear quickly at brunches and potlucks.

Required Tools

12-cup muffin tin, mixing bowl, whisk, knife and cutting board, oven

Allergen Information

Contains eggs, milk (dairy), cheese (dairy). May contain pork if using bacon/sausage. For dairy-free versions, use plant-based milk and cheese. Always check labels for processed ingredients.

Nutritional Information

Per muffin with bacon and cheddar: 130 calories, 9 g total fat, 2 g carbohydrates, 9 g protein

Fluffy, cheesy One-Pot Breakfast Casserole Muffins with visible chunks of red bell pepper and spinach; a delicious, easy meal. Save
Fluffy, cheesy One-Pot Breakfast Casserole Muffins with visible chunks of red bell pepper and spinach; a delicious, easy meal. | butterhollow.com

Enjoy these breakfast casserole muffins warm out of the oven, or save a batch for healthy meals all week.

Kitchen Tips & Answers

Can I make these muffins vegetarian?

Yes, simply omit the bacon or sausage and add extra vegetables like mushrooms or zucchini for added flavor and texture.

How do I store the muffins for later use?

Store in an airtight container in the refrigerator for up to 4 days or freeze for up to 2 months. Reheat in a microwave or oven before serving.

What type of cheese works best in these muffins?

Shredded cheddar or Monterey Jack cheese melt beautifully and complement the savory ingredients well, but feel free to use your favorite cheese.

Can I substitute the milk with a dairy-free option?

Absolutely, use plant-based milk alternatives such as almond or oat milk to keep it dairy-free without sacrificing texture.

What temperature and time should I bake the muffins?

Preheat the oven to 350°F (175°C) and bake for 22 to 25 minutes until the muffins are set and lightly golden on top.

One-Pot Breakfast Casserole Muffins

Savory muffins packed with eggs, cheese, and fresh vegetables, ideal for quick and portable breakfasts.

Prep duration
15 min
Heat duration
25 min
Complete duration
40 min
Created by Ella Thompson

Type Warm Bakes

Skill level Easy

Heritage American

Output 12 Portions

Eating preferences No gluten, Carb-Conscious

What you'll need

Base

01 8 large eggs
02 1/3 cup whole milk or dairy-free alternative

Vegetables

01 1 cup chopped baby spinach
02 1/2 cup diced red bell pepper
03 1/2 cup finely chopped onion

Protein (optional)

01 3/4 cup cooked bacon or breakfast sausage, crumbled

Cheese

01 1 cup shredded cheddar or Monterey Jack cheese

Seasonings

01 1/2 teaspoon salt
02 1/4 teaspoon black pepper
03 1/4 teaspoon smoked paprika

Oils

01 1 tablespoon olive oil or nonstick spray for greasing muffin tin

Method

Phase 01

Preheat and prepare tin: Preheat oven to 350°F. Grease a 12-cup muffin tin with olive oil or nonstick spray.

Phase 02

Mix eggs and milk: In a large bowl, whisk eggs and milk until fully combined.

Phase 03

Combine ingredients: Fold in chopped spinach, diced bell pepper, chopped onion, crumbled cooked bacon or sausage (if using), shredded cheese, salt, black pepper, and smoked paprika.

Phase 04

Fill muffin cups: Divide mixture evenly among muffin cups, filling each about three-quarters full.

Phase 05

Bake muffins: Bake for 22 to 25 minutes until set and lightly golden.

Phase 06

Cool and serve: Let muffins cool in the tin for 5 minutes, then loosen edges with a knife and remove. Serve warm or cool completely for storage.

Kitchen tools needed

  • 12-cup muffin tin
  • Mixing bowl
  • Whisk
  • Knife and cutting board
  • Oven

Allergy details

Always review individual ingredients for potential allergens and seek professional medical guidance if uncertain.
  • Contains eggs and dairy from milk and cheese.
  • May contain pork if bacon or sausage is included.

Nutrient breakdown per portion

Numbers shown are estimates only - consult healthcare providers for specific advice.
  • Energy: 130
  • Fats: 9 g
  • Carbohydrates: 2 g
  • Proteins: 9 g