Copycat Costco Chocolate Muffin Recipe

These decadent chocolate muffins are inspired by the famous Costco chocolate muffins, known for their rich cocoa flavor, tender crumb, and generous chocolate chips. Perfectly moist and packed with chocolatey goodness, these jumbo muffins are the ultimate treat for chocolate lovers. Whether you’re enjoying them for breakfast or as a dessert, they’re sure to satisfy your sweet tooth!

Ingredients

• 1 2/3 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

Instructions

Step 1: Preheat the Oven

1. Preheat your oven to 375°F (190°C) .
2. Line a 6-cup jumbo muffin tin with jumbo cupcake liners or lightly grease each cup to prevent sticking.

Step 2: Bloom the Cocoa Powder

1. In a small bowl, whisk together ¼ cup of cocoa powder and ½ cup of hot water until smooth. This step enhances the cocoa’s flavor.
2. Set the mixture aside to cool slightly while you prepare the other ingredients.

Step 3: Mix the Dry Ingredients

1. In a medium bowl, whisk together the flour , remaining ½ cup of cocoa powder , baking powder , baking soda , and salt until evenly combined. Set aside.

Step 4: Prepare the Wet Ingredients

1. In a large mixing bowl, whisk together the granulated sugar , vegetable oil , eggs , egg yolk , and vanilla extract until smooth and well combined.
2. Stir in the sour cream and the prepared cocoa mixture , mixing until fully incorporated.

Step 5: Combine Wet & Dry Ingredients

1. Gradually add the dry ingredients to the wet ingredients, stirring gently until just combined. Avoid overmixing, as this can lead to dense muffins. The batter will be thick but should still be scoopable.

Step 6: Fold in the Chocolate Chips

1. Reserve ½ cup of chocolate chips for topping.
2. Gently fold the remaining 2 cups of chocolate chips into the batter to ensure even distribution.

Step 7: Fill & Top the Muffins

1. Evenly distribute the batter among the prepared muffin cups, filling each about three-quarters full .
2. Sprinkle the reserved ½ cup of chocolate chips evenly on top of each muffin for an extra chocolatey finish.

Step 8: Bake the Muffins

1. Bake for 25–30 minutes , or until a toothpick inserted into the center of a muffin comes out with a few moist crumbs but no wet batter.
2. The tops should be domed and slightly cracked, with a rich chocolate aroma filling your kitchen.

Step 9: Cool & Serve

1. Let the muffins cool in the tin for 10 minutes , then transfer them to a wire rack to cool completely.
2. Enjoy warm or at room temperature for the ultimate chocolatey indulgence!

Tips for Success

• Room Temperature Ingredients: Make sure the eggs, egg yolk, and sour cream are at room temperature for a smoother batter and better rise.
• Jumbo Muffin Tin: If you don’t have a jumbo muffin tin, use a standard 12-cup muffin tin and reduce the baking time to 18–22 minutes .
• Chocolate Chips: Use high-quality semi-sweet chocolate chips for the best flavor and texture. You can also mix in dark or milk chocolate chips for variety.
• Storage: Store muffins in an airtight container at room temperature for up to 3 days or in the refrigerator for up to 5 days . Reheat briefly in the microwave for a warm treat.
• Freezing: These muffins freeze beautifully! Wrap individually in plastic wrap and store in a freezer-safe bag for up to 3 months . Thaw at room temperature before serving.

Why You’ll Love This Recipe

These Copycat Costco Chocolate Muffins are everything you’d want in a bakery-style muffin—rich, moist, and loaded with chocolate. The bloomed cocoa powder ensures deep chocolate flavor, while the sour cream adds incredible moisture and tenderness. Topped with extra chocolate chips, these jumbo muffins are impossible to resist. Whether you’re recreating the nostalgia of Costco’s iconic muffins or simply craving a homemade chocolate treat, this recipe delivers perfection every time. Dive into these chocolatey delights and savor every bite!