Banana Chocolate Chip Muffins With A Sweet, Crunchy Crumb Topping...

Banana Chocolate Chip Muffins With A Sweet, Crunchy Crumb Topping (Copycat Costco Recipe)

Michelle Bottalico/Mashed

We may receive a commission on purchases made from links.

Costco's banana chocolate chip muffins were a classic favorite for years. The muffins featured a noticeable banana aroma and flavor and a generous number of chocolate chunks dotting the inside. A crumb topping and more chocolate chunks completed the sweet treat, which was also notable for its jumbo size.

Why the past tense? Sadly, these muffins appear to have been discontinued at Costco. Luckily, recipe developer Michelle Bottalico has created a copycat recipe for Costco banana chocolate chip muffins that allows you to resurrect these popular treats right at home. Overripe bananas are responsible for the noticeable banana flavor in these muffins (they also contribute added moisture and sweetness), and chocolate chunks provide more concentrated chocolatey goodness than chocolate chips do. Of note is the canola oil, which is used instead of butter for extra moist muffins, and sour cream, which adds even more moisture. The muffins are topped with an irresistible sugary and buttery crumb topping and more chocolate chunks — just like Costco used to make, but possibly even better.

Gather your copycat Costco banana chocolate chip muffin ingredients

banana chocolate chip muffin ingredients on table

Michelle Bottalico/Mashed

For this recipe you will first need all-purpose flour, baking soda, salt, and cinnamon. Then grab some overripe bananas, which are key for a sweeter muffin. You will also need granulated sugar, canola oil, a large egg, sour cream, vanilla extract, and chocolate chunks. The ingredients for the sweet crumb topping are all-purpose flour, granulated sugar, light brown sugar, salted butter (melted), and chocolate chunks.

Step 1: Preheat the oven

Michelle Bottalico/Mashed

Preheat the oven to 375 F.

Step 2: Line the muffin tin

Michelle Bottalico/Mashed

Step 3: Mix the dry ingredients

Michelle Bottalico/Mashed

Place the flour, baking soda, salt, and cinnamon in a mixing bowl and whisk until evenly combined.

Step 4: Mix the wet ingredients

Michelle Bottalico/Mashed

Add the mashed banana, sugar, oil, egg, sour cream, and vanilla to a second mixing bowl and whisk well to combine.

Step 5: Combine dry and wet mixtures to form the muffin batter

Michelle Bottalico/Mashed

Gradually add the flour mixture into the bowl of wet ingredients while stirring with a wooden spoon until just combined. Do not overmix.

Step 6: Fold in the chocolate chunks

chocolate chunk muffin batter in mixing bowl

Michelle Bottalico/Mashed

Gently fold in the ¾ cup of chocolate chunks.

Step 7: Fill the muffin tin

Michelle Bottalico/Mashed

Evenly divide the batter among the 12 cups of the muffin tin. Set aside.

Step 8: Start the crumb topping

Michelle Bottalico/Mashed

Start making the crumb topping by placing the flour, granulated sugar, and light brown sugar in a bowl and mixing until well combined.

Step 9: Add butter to form the crumbs

Michelle Bottalico/Mashed

Add the melted butter and use a fork to combine the mixture just until it's clumpy and crumbly. Do not overmix or you will lose the crumbs.

Step 10: Sprinkle the crumb topping onto the muffins

Michelle Bottalico/Mashed

Sprinkle the crumb topping evenly on top of the muffins.

Step 11: Add the chocolate chunks

Michelle Bottalico/Mashed

Top the muffins with 6 tablespoons of chocolate chunks, evenly dispersing the chunks across each muffin.

Step 12: Bake the muffins

Michelle Bottalico/Mashed

Bake the muffins for 18-20 minutes, or until a toothpick inserted into the center of a muffin comes out clean. Rotate the pan halfway for even baking.

Step 13: Serve the copycat Costco banana chocolate chip muffins

Michelle Bottalico/Mashed

Remove the muffins from the oven and let cool for 5 minutes in the pan, and then transfer to a wire rack to cool completely before serving, about 1 hour.

What to serve with copycat Costco banana chocolate chip muffins

Enjoy Costco's beloved banana chocolate chip muffins - the ones loaded with chocolate chunks and finished with a crumb topping - right at home with this recipe.

chocolate banana muffins on stand

Total time: 1 hour, 38 minutes

For the muffins
1 ½ cups all-purpose flour
1 teaspoon baking soda
½ teaspoon salt
½ teaspoon cinnamon
1 cup mashed overripe banana, from about 3 medium bananas
¾ cup granulated sugar
½ cup canola oil
1 large egg
2 tablespoon sour cream
1 teaspoon vanilla extract
¾ cup chocolate chunks
For the crumb topping
½ cup + 1 tablespoon all-purpose flour
3 tablespoons granulated sugar
3 tablespoons light brown sugar
3 tablespoons salted butter, melted
6 tablespoons chocolate chunks

Preheat the oven to 375 F.
Line a 12-cup muffin tin with paper liners.
Place the flour, baking soda, salt, and cinnamon in a mixing bowl and whisk until evenly combined.
Add the mashed banana, sugar, oil, egg, sour cream, and vanilla to a second mixing bowl and whisk well to combine.
Gradually add the flour mixture into the bowl of wet ingredients while stirring with a wooden spoon until just combined. Do not overmix.
Gently fold in the ¾ cup of chocolate chunks.
Evenly divide the batter among the 12 cups of the muffin tin. Set aside.
Start making the crumb topping by placing the flour, granulated sugar, and light brown sugar in a bowl and mixing until well combined.
Add the melted butter and use a fork to combine the mixture just until it's clumpy and crumbly. Do not overmix or you will lose the crumbs.
Sprinkle the crumb topping evenly on top of the muffins.
Top the muffins with 6 tablespoons of chocolate chunks, evenly dispersing the chunks across each muffin.
Bake the muffins for 18-20 minutes, or until a toothpick inserted into the center of a muffin comes out clean. Rotate the pan halfway for even baking.
Remove the muffins from the oven and let cool for 5 minutes in the pan, and then transfer to a wire rack to cool completely before serving, about 1 hour.

Calories per Serving	360
Total Fat	18.0 g
Saturated Fat	5.8 g
Trans Fat	0.2 g
Cholesterol	24.3 mg

Total Carbohydrates	49.3 g
Dietary Fiber	2.1 g
Total Sugars	29.3 g
Sodium	219.2 mg
Protein	3.7 g

The information shown is Edamam’s estimate based on available ingredients and preparation. It should not be considered a substitute for a professional nutritionist’s advice.

What are tips for ensuring successful copycat Costco muffins?

Michelle Bottalico/Mashed

Knowing how to measure flour correctly is the first step to successful muffins. Make sure to spoon the flour into your measuring cups, without pressing the spoon down and compacting the flour, and then level the cups. For the most accurate results, use a food scale. Then it won't matter how you scoop it because it will always have the same weight. Make sure your baking soda hasn't expired as well. Test it by adding a little vinegar or lemon juice and making sure it fizzes. Using overripe bananas is also key or the muffins won't be as sweet.

After you add the dry ingredients to the wet ingredients in the mixing bowl, stir just until the mixture comes together. Don't overmix or the muffins can come out tough, when light and fluffy is the goal. That's why the directions say to use a wooden spoon and not an electric beater. Watch the muffins when baking with the oven light, and avoid opening the as much as possible door because it lowers the oven temperature. Check the muffins by inserting a toothpick into the center — it should come out virtually clean or with just a small amount of crumbs sticking to it, but you should not see wet batter.

How can I customize these banana chocolate chip muffins?

Michelle Bottalico/Mashed

There are many ways to customize banana chocolate chip muffins according to your diet, preferences, or ingredient availability. This recipe calls for chocolate chunks, but chocolate chips would be equally delicious. Chocolate lovers can turn these into chocolate banana muffins by adding cocoa powder to the dry ingredients, which would give the muffins a dark brown chocolate appearance. For a different visual effect and extra banana flavor, thinly slice a small banana and arrange the slices on top of the muffins. You can add nuts like walnuts or pecans to the batter for crunch. Toast the nuts first for a more robust taste.

This recipe calls for a sweet and textured crumb topping made with flour, granulated sugar, brown sugar, and butter. You can omit the crumb topping if desired and top the muffins with chocolate chunks or chocolate chips only, or omit a topping altogether and leave them plain. Or, for a sweet topping that's more lightweight, sprinkle coarse decorating sugar on the muffin batter in the tins before baking. You could also sub other fruit for the bananas for a spin with a different flavor. Unsweetened applesauce is a good sub for mashed banana. Like applesauce, pureed fruit like pears, blueberries, strawberries, or your favorite fruit can also be used in a 1:1 substitution ratio.