Craving those oversized, rich chocolate muffins from Costco? These Copycat Costco Chocolate Muffins are just as moist, fudgy, and packed with melty chocolate chips—right from your own kitchen. Whether you’re baking for breakfast, brunch, or dessert, these muffins deliver bakery-quality flavor and texture every time.

Why You’ll Love This Chocolate Muffin Recipe

These muffins are:

• Ultra-moist with rich chocolate flavor

• Loaded with chocolate chips in every bite

• Easy to make with pantry staples

• Perfect for breakfast, snacks, or dessert

• Just like the iconic Costco version—only homemade

If you love big, bakery-style muffins that taste indulgent and comforting, this recipe is for you.

Ingredients You’ll Need

• 1⅔ cups all-purpose flour

• 2 teaspoons baking powder

• ½ teaspoon baking soda

• 1 teaspoon kosher salt

• ¾ cup unsweetened cocoa powder, divided

• ½ cup hot water

• 1 cup granulated sugar

• ⅓ cup vegetable oil

• 2 large eggs plus 1 yolk, at room temperature

• 2 teaspoons pure vanilla extract

• ¾ cup sour cream, at room temperature

• 15 ounces semi-sweet chocolate chips (about 2½ cups), divided

How to Make Copycat Costco Chocolate Muffins

Prep Time: 15 minutes
Cook Time: 20 minutes
Total Time: 35 minutes
Servings: 12
Calories: 350 kcal per muffin

1. Preheat the Oven

Preheat your oven to 350°F (175°C) and line a 12-cup muffin tin with paper liners.

2. Combine Dry Ingredients

In a medium bowl, whisk together the flour, baking powder, baking soda, salt, and ½ cup of the cocoa powder.

3. Dissolve Sugar

In a large bowl, stir the hot water and granulated sugar until the sugar dissolves.

4. Mix Wet Ingredients

Add the oil, eggs, egg yolk, vanilla, and sour cream to the sugar mixture. Whisk until smooth.

5. Combine Wet and Dry

Gradually add the dry ingredients to the wet, stirring just until no dry streaks remain.

6. Add Chocolate

Fold in 1¾ cups of the chocolate chips along with the remaining ¼ cup cocoa powder.

7. Fill the Muffin Cups

Divide the batter evenly among the muffin cups, filling each about ¾ full.

8. Add Topping

Sprinkle the remaining chocolate chips over the tops of the muffins.

9. Bake

Bake for 18–20 minutes, or until a toothpick inserted in the center comes out clean or with moist crumbs.

10. Cool

Let the muffins cool in the pan for 5 minutes, then transfer to a wire rack to cool completely.

Ways to Serve These Muffins

• Enjoy warm with a glass of milk or coffee

• Add to a brunch spread with fruit and yogurt

• Serve as an after-school snack or late-night treat

• Wrap individually for lunchboxes or on-the-go breakfasts

• Warm slightly and serve with vanilla ice cream for dessert

Tips & Variations

• Don’t overmix the batter—stop as soon as the dry ingredients disappear

• Use full-fat sour cream for the richest texture

• You can substitute part of the chocolate chips with mini chips or chopped chocolate chunks

• To make jumbo muffins, use a jumbo tin and bake for 22–25 minutes

• Add a teaspoon of espresso powder for an even deeper chocolate flavor

Frequently Asked Questions

How do I make these muffins extra moist like Costco’s?
The combination of sour cream, oil, and extra egg yolk keeps these muffins soft and moist. Avoid overbaking to maintain that rich texture.

Can I make them ahead of time?
Yes. These muffins keep well for 2–3 days at room temperature in an airtight container, or up to 5 days in the fridge.

Can I freeze these muffins?
Absolutely. Once cooled, wrap individually and freeze for up to 2 months. Thaw at room temperature or microwave for 20–30 seconds to warm.

Why do I use both cocoa powder and chocolate chips?
Cocoa powder gives a deep chocolate base, while the chocolate chips provide bursts of sweetness and gooey texture throughout the muffin.

Can I substitute yogurt for sour cream?
Yes, plain full-fat Greek yogurt works well as a substitute, though it may result in a slightly tangier flavor.

Final Thoughts

These Copycat Costco Chocolate Muffins bring all the decadence of the original into your own kitchen. With a rich chocolate crumb, melty chips, and a soft, bakery-style texture, they’re sure to satisfy any chocolate craving. Whether you’re baking for a crowd or just for yourself, this is a recipe you’ll return to again and again.