Costco Chocolate Muffins Recipe: Big, Moist, Bakery-Style Treats

There’s something irresistible about those jumbo Costco chocolate muffins—they’re rich, moist, and packed with melty chocolate in every bite. But what if you could enjoy that same indulgent experience straight from your own kitchen? In this guide, we’ll show you how to recreate the famous Costco double chocolate muffins using simple ingredients, smart baking techniques, and step-by-step tips. Whether you’re baking for brunch, freezing for later, or whipping up a chocolate fix, these bakery-style muffins will never disappoint. Don’t miss our fudgy-chewy brookies recipe if you’re into gooey chocolate bakes!

JUMP TO

Table of Contents

Why Costco Chocolate Muffins Are So Addictive

The Signature Flavor and Texture

What sets Costco chocolate muffins apart is their deep, chocolaty punch wrapped in an incredibly moist crumb. Unlike regular cupcakes, these muffins lean into a dark cocoa richness enhanced by semi-sweet chocolate chips. Each bite delivers both a soft, cakey texture and a hit of gooey melted chocolate—pure magic. That lush consistency comes from the high-fat ingredients, precise mixing, and their size, which helps trap moisture during baking.

What Makes Them Bakery-Style and Jumbo-Sized

You’ve probably noticed that Costco Chocolate Muffins aren’t your average breakfast treat. They’re bakery-style—meaning they rise high, crack beautifully at the top, and weigh in at nearly 800 calories each. This is no accident. Using a jumbo muffin tin and starting with high oven heat creates that iconic dome. Plus, the batter’s thickness (thanks to sour cream and buttermilk) helps the muffins hold shape while staying ultra-moist inside.

Want more ideas for bold, big-batch bakes? Check out our no-knead bread recipe for another satisfying homemade classic.

Nutrition Facts and Serving Size Breakdown

Let’s be honest—these muffins aren’t diet food, but they’re worth every bite. A single muffin comes in around:

Nutrient	Amount per Jumbo Muffin
Calories	793
Carbohydrates	116g
Protein	14g
Total Fat	33g
Sugar	67g
Fiber	10g
Sodium	727mg
Iron	8mg

Yes, they’re indulgent. But they’re also freezer-friendly, make-ahead-friendly, and way cheaper than buying in-store. For those who crave chocolate but want a more moderate option, try our blueberry cream cheese bars for a fruity twist.

Want a savory balance to all this sweetness? Discover great ideas like garlic butter chicken and potatoes skillet—a perfect pairing for a rich dessert finale.

Ingredients You’ll Need for Copycat Costco Chocolate Muffins

Baking muffins that taste just like Costco’s starts with the right ingredients—and a few key techniques. Here’s a breakdown of what you’ll need to create ultra-moist, bakery-style chocolate muffins at home.

Essential Pantry Staples

Start with the basics:

• All-purpose flour (1¾ cups) – Provides the structure for these big muffins. Spoon and level it for accuracy.
• Unsweetened cocoa powder (⅔ cup) – This is where the deep chocolate flavor begins. Go for Dutch-processed if you want a smoother finish.
• Baking powder & baking soda – Together, they ensure these muffins rise high without becoming too dense.
• Salt – Just 1 teaspoon balances the sweetness and enhances the chocolate.

Optional but impactful:

• Espresso powder (1 tsp) – It won’t make the muffins taste like coffee, but it will intensify the chocolate flavor. Trust us, it’s a game changer.

If you love bold flavor, don’t miss our black magic cake recipe—it also uses espresso for depth!

The Moisture Boosters: Sour Cream and Buttermilk

Here’s where Costco’s texture secret really lies:

• Sour cream (½ cup) – Adds richness and acidity, making muffins ultra-moist without being greasy.
• Buttermilk (¾ cup) – The acidity here also activates baking soda for a better rise, while creating a tender crumb.

Don’t have buttermilk? No problem. Add 1 tablespoon of vinegar or lemon juice to a cup of milk and let it sit for 5 minutes. Or use whole milk in a pinch—your muffins will still turn out rich, thanks to the sour cream.

Fun tip: Full-fat Greek yogurt is a solid sub for sour cream. We’ve used it in this creamy rigatoni with sausage recipe with excellent results.

Chocolate Lovers’ Dream: Chips and Cocoa Powder

Now for the fun part—chocolate.

• Chocolate chips (2 cups total) – Use semi-sweet chips for a balance of sweet and bitter. Fold in 1½ cups, and reserve ½ cup to press on top of the batter for that iconic chocolate-loaded look.
• Cocoa powder – As mentioned, this gives the base its dark chocolate richness. Don’t skimp or swap it for sweetened cocoa mix—it won’t deliver the same punch.

Using real, quality chocolate chips makes all the difference—just like in our chewy snickerdoodle cookies, where richness comes from balanced ingredients.

Step-by-Step Instructions to Make Costco Chocolate Muffins at Home

Once you’ve gathered your ingredients, it’s time to bring these jumbo bakery-style muffins to life. The process is easy, and with a few smart baking tricks, you’ll get perfect results every time.

Prepping Your Jumbo Muffin Pan

Start by preheating your oven to 425°F. This initial high temperature helps create that signature muffin dome.
Use a jumbo 6-count muffin tin for authentic Costco-size muffins. Line the cups with jumbo muffin liners or grease them well if you prefer a crustier edge.

Want to try another oversized treat? Looking for inspiration? Try our California Pizza Kitchen butter cake recipe—it’s just as indulgent.

Mixing Wet and Dry Ingredients Separately

Don’t just toss everything in one bowl. For bakery-worthy results, whisk your dry ingredients separately:

• Flour
• Cocoa powder
• Baking powder
• Baking soda
• Salt
• Espresso powder (optional)

In a large mixing bowl, combine the melted, slightly cooled butter with granulated sugar and whisk until smooth. Add the eggs one at a time, then stir in the vanilla extract, sour cream, and buttermilk.

This layering approach ensures that everything emulsifies properly, creating a rich and tender crumb without overmixing.

Folding and Resting the Batter

Next, gently fold your dry ingredients into the wet using a spatula or large spoon. Add 1½ cups chocolate chips, saving the rest to top the muffins later.
Your batter will be thick—that’s good! It helps create structure. Let the batter rest for 10–15 minutes at room temperature to hydrate the flour and boost the rise.

During the rest, explore other big batch dessert ideas like our no-bake banana split cake for a fun, chilled twist on a classic.

Baking Tips for Perfect Rise and Moist Center

Now it’s time to scoop! Divide the batter evenly between the six jumbo muffin liners. Press in the remaining chocolate chips on top.
Bake at 425°F for 5 minutes, then—without opening the oven—lower the temperature to 350°F and bake for another 19–25 minutes.

You’ll know they’re done when a toothpick inserted into the center comes out with a few moist crumbs—not wet batter.

Avoid opening the oven too early, which can cause the centers to sink. Also, don’t overbake—these muffins should be moist and fudgy, not dry.

Let them cool in the pan for 5–10 minutes before removing. Enjoy them warm, or store them for later. For another muffin idea, don’t miss our easy breakfast egg muffins—a savory complement to these chocolatey treats.

Smart Baking Tips for Better Chocolate Muffins

Whether you’re a seasoned baker or just starting out, these expert tips will help ensure your Costco-style muffins come out rich, moist, and bakery-perfect every single time.

Why Room Temperature Ingredients Matter

Using room temperature eggs, sour cream, and buttermilk is more than just a suggestion—it’s essential. When your wet ingredients are at similar temperatures, they mix more easily, creating a smoother batter. This results in better texture, even baking, and maximum rise. Cold ingredients can cause butter to seize or clump, leading to uneven results.

Tip: To bring eggs to room temp quickly, place them in a bowl of warm water for 10 minutes.

The Science of Baking at Two Temperatures

That high-to-low baking method? It’s not random—it’s science. Starting at 425°F helps the muffin tops puff up quickly, forming that signature bakery-style dome. Lowering the oven to 350°F afterward ensures the insides bake through without drying out or burning the edges.

This same strategy works wonders in other bakes, like our strawberry cream cheese pie—delicate filling, strong crust!

How to Avoid Dense or Dry Muffins

Overmixing is your enemy here. Once you combine the wet and dry ingredients, mix just until combined—no more. Overworking the batter develops gluten, making muffins tough or rubbery instead of light and fluffy.

Also, don’t skip the resting period. Allowing the batter to sit for 10–15 minutes lets the flour hydrate and the leavening agents activate—this gives your muffins a taller, more even rise.

If you’re after equally moist, fuss-free baking, discover our moist chocolate cupcakes—they follow similar moisture-locking rules.

Storage, Freezing, and Make-Ahead Options

These muffins aren’t just indulgent—they’re also incredibly convenient. Whether you’re meal prepping, saving leftovers, or gifting them, here’s how to keep your chocolate muffins fresh and delicious.

How Long Do They Last?

At room temperature, store muffins in an airtight container for 2–3 days. Line the container with a paper towel to absorb any moisture that might make the tops sticky.

In the fridge, they’ll last up to one week. Let them come to room temp or give them a quick warm-up in the microwave before enjoying.

For more long-lasting recipes, don’t miss our cinnamon roll French toast roll—a brunch hit that holds up beautifully.

Best Ways to Freeze and Reheat

Want to enjoy these muffins later? Freezing is a breeze:

• Let muffins cool completely
• Wrap each in plastic wrap, then place in a freezer-safe bag or container
• Label with the date and freeze for up to 3 months

To reheat, unwrap and microwave for 30–40 seconds or bake at 300°F for 10 minutes. They’ll taste freshly baked all over again.

Try the same freezer method with our air fryer baked potato—it’s great for batch cooking.

Making Mini or Regular-Sized Muffins

Not in the mood for jumbo muffins? No problem. Use a standard muffin tin and reduce the baking time:

• Bake at 425°F for 5 minutes, then at 350°F for 10–12 minutes

This recipe can also be used to make mini muffins—just adjust the final bake time to 8–10 minutes depending on your oven. Keep an eye on the centers and test with a toothpick.

Explore more mini-friendly bakes like our chewy brown sugar cookies—they’re great for sharing.

FAQs About Costco Chocolate Muffins

Final Thoughts on Recreating Costco’s Famous Muffins

Recreating the iconic Costco chocolate muffins at home is easier than you’d think—and even more satisfying. With rich chocolate flavor, jumbo bakery-style texture, and freezer-friendly convenience, this recipe is a chocolate lover’s dream. By following the temperature trick and using quality ingredients like sour cream and buttermilk, you’ll achieve moist, fluffy muffins that rival (or even beat) the store version.

Looking for your next bake? Check out our blueberry peach cheesecake—it’s another decadent crowd-pleaser worth every bite.

Print