
Why You’ll Love This Recipe
You need to know, right off the bat, that I feel slightly guilty calling these muffins. If you’ve ever had the Costco version, you know what I mean. They aren’t fooling anybody. Because these so-called “muffins” are actually rich, moist, chocolate cupcakes….without frosting.
- Just like the store version—maybe better: If you love those oversized, ultra-chocolatey muffins from Costco, this homemade version brings that same rich flavor, with even more love baked in.
- Shortcuts make it so easy: This recipe starts with a cake mix and pudding mix, so you get bakery-style results without the fuss. No complicated steps—just mix, scoop, and bake!
- Bakery-style results: Thanks to the addition of sour cream, these muffins come out incredibly moist and tender with a perfect, soft crumb.
- Great for meal-prep: Double the recipe and stash some in the freezer for a quick breakfast or snack on-the-go.
After you preview the recipe card, be sure to look below for ingredient substitutions, recipe and storage tips, and suggestions for pairings and tasty variations!
Double Chocolate Muffins (Costco Copycat Recipe)
These homemade double chocolate muffins are just as rich and moist as the originals, but even better because they’re fresh from your own oven. With simple ingredients and a shortcut cake mix base, you’ll have bakery-style muffins in no time.
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Servings: 24
Calories: 246kcal
Ingredients
- 3 eggs
- 1/2 cup canola oil
- 1/2 cup milk
- 1/4 cup water
- 1 teaspoon vanilla
- 1 cup sour cream
- 1 package Devil’s food cake mix
- 1 3.9 oz package instant chocolate pudding mix
- 1/2 teaspoon cinnamon
- 2 1/2 cups semisweet chocolate chips divided
Instructions
- Preheat oven to 375 degrees. Line muffins tins with paper liners.
- In a large bowl, lightly beat 3 eggs. Mix in 1/2 cup canola oil, 1/2 cup milk, 1/4 cup water, and 1 teaspoon vanilla.
- Stir in the 1 cup sour cream, 1 package Devil’s food cake mix, the1 3.9 oz package instant chocolate pudding mix and 1/2 teaspoon cinnamon. Mix well. Stir in 2 cups of the chocolate chips.
- Fill muffin tins 3/4 full. Sprinkle the remaining 1/2 cup chocolate chips over the batter. Bake for 15-20 minutes or until a toothpick inserted in the center comes out clean.
Nutrition
Serving: 1g | Calories: 246kcal | Carbohydrates: 31g | Protein: 3g | Fat: 13g | Saturated Fat: 5g | Polyunsaturated Fat: 7g | Cholesterol: 30mg | Sodium: 192mg | Fiber: 1g | Sugar: 20g
Keep scrolling for tips, ingredient substitutions, answers to frequently asked questions and more!

Recipe Tips
- Don’t overmix! Once you add the dry ingredients, mix until everything is just combined. Overmixing can make the muffins dense.
- Use a spring-loaded ice cream scoop to fill each muffin cup about 3/4 full. This will help achieve those beautiful domed muffin tops.
- Check for doneness early: Ovens can vary, so start checking at the 15-minute mark. A toothpick inserted in the center should come out with a few moist crumbs.
- Make jumbo or regular sized muffins: You’ll get about 2 dozen regular sized muffins from this recipe. Or one dozen if you make them in a jumbo muffin pan.
Storing and Freezing
Tips for Storing
- Cool completely before storing to prevent condensation and sogginess.
- Store in an airtight container at room temp for up to 3 days. Try placing a paper towel underneath and on top of the muffins to absorb excess moisture and keep the tops from getting sticky.
- Pop your muffins in the microwave for 10–15 seconds to bring back that fresh from the oven goodness.
Tips for Freezing
- Freeze individually: Wrap each muffin tightly in plastic wrap or foil, then place in a freezer-safe zip-top bag or container. This helps prevent freezer burn and makes it easy to grab just one at a time. Freeze for up to 3 months.
- Let muffins thaw at room temp for about an hour, or microwave straight from frozen for 30–40 seconds for a warm, fresh-baked taste.

Variations and Fun Twists
- Chocolate Hazelnut: Swirl a spoonful of Nutella into the center of each muffin before baking.
- Triple Chocolate: Use a combo of semisweet, milk, and white chocolate chips for added variety.
- Chocolate Orange: Add a few teaspoons of orange zest to the batter for a bright contrast to the rich chocolate.
- Banana Chocolate Muffins: Replace the sour cream with mashed banana.






34 comments
Mary
Haven’t made them yet Doesn’t tell me the calories
Jann
I’ve made these are they are amazing! Big hit with my adult kids too. I made some full sized muffins and some muffin tops. I’m sugar sensitive and even the muffin tops were too much for me. But, they are delicious!
Lynn
I just finished making these to accompany the poem “If you Give a Mom a Muffin” for our eighth graders to sell at their mother’s day bake sale and I have to confess… I had to try one to validate the incredible smell. So glad I did! They turned out terrific. I used Nestle mini chips as well as some full size dark chocolate chips. I filled the cups to the 3/4+ mark and they came out with a nice little dome on top after 18 minutes of bake time. The recipe made 25 muffins. Thanks for a recipe I am sure to make again (many times).
Ian McCallum
I followed the recipe to the letter, although as my posted question earlier there is no stated amount of cake mix ie. only x1. I opted for 420g. They tasted superb but really soggy in the middle and no rise or very little.
Danelle
Sorry, just seeing this! It’s the whole cake mix. Sizes can vary a bit, but most of them should work.
Ian McCallum
How much cake mix? It only says x1!
Jann
I just made these and they smell amazing! My daughter had one warm from the oven and thought they were delicious. I can’t handle the sugar in a full muffin so I made 12 muffins and 21 muffin tops. They all came out perfect!
Bernadette
Just decided not to make these after I bought all the ingredients…the majority of your comments are not about how the recipe turned out but people saying how good they look. I want to hear about the recipe. You should only post those
Lisa
This is why I *always* read the comments before I even save a recipe much less buy ingredients for and/or make any recipe on Pinterest. Unless 90% of comments are strictly negative (i.e., fell apart, tasted too dry, took longer than stated time to cook, etc ), I still make the recipe for myself & form my own opinion & not just because people described the looks of the dish only. Life happens & maybe they weren’t able to taste the recipe yet, waiting for the 10 mins in the recipe to cool. but still wanted to comment??? Because, you know, Life Happens.