Craving those giant, ultra-chocolatey Costco muffins without the warehouse run? You can bake the same rich flavor and sky-high muffin tops at home with simple pantry ingredients. This copycat Costco chocolate muffins recipe nails the moist crumb, deep cocoa taste, and those melty chocolate pockets in every bite.

I’ll walk you through the exact steps for tall domes, bakery-style texture, and that signature glossy top. No special equipment needed—just smart mixing, a hot oven kickstart, and a batter that brings big chocolate energy. Let’s bake a batch you’ll brag about.

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Why This Copycat Chocolate Muffin Recipe Works

High-domed muffins: We start hot, then reduce the temperature. That encourages rapid lift and tall, bakery-style tops.
Double chocolate depth: Cocoa powder plus chocolate chips create intense flavor and gooey bits throughout.
Moist, tender crumb: Oil, buttermilk, and eggs lock in moisture so muffins stay soft for days.
Not too sweet: Balanced sugar lets the chocolate shine, just like the store-bought version.
Big-batch friendly: The batter scales easily and bakes beautifully in jumbo or standard tins.

Ingredients

Dry Ingredients

All-purpose flour – provides structure without heaviness
Natural unsweetened cocoa powder – classic cocoa flavor; sift to remove lumps
Granulated sugar – sweetness and moisture retention
Brown sugar – adds moisture and a hint of caramel depth
Baking powder – primary lift
Baking soda – reacts with buttermilk for extra rise
Kosher salt – balances the sweetness and enhances chocolate flavor
Espresso powder (optional) – boosts chocolate notes without tasting like coffee
Chocolate chips – semi-sweet or dark; reserve a handful for topping

Wet Ingredients

Buttermilk – tenderness and tang; see substitutions below
Neutral oil (canola, vegetable, or light olive) – keeps crumb moist
Large eggs – bind and add richness
Vanilla extract – rounds out chocolate flavor
Hot water – blooms cocoa for deeper flavor and a looser, scoopable batter

Substitutions

No buttermilk? Use whole milk with 1 tablespoon lemon juice or vinegar per cup. Rest 5 minutes.
Dairy-free? Use unsweetened almond or oat milk with 1 tablespoon vinegar per cup, and dairy-free chips.
Gluten-free? Use a 1:1 gluten-free baking blend with xanthan gum included.
Sweeter muffin? Add 2–3 tablespoons extra sugar or use milk chocolate chips.

How to Make Big, Bakery-Style Chocolate Muffins

Before You Start

Preheat to 425°F (218°C). Grease a 12-cup muffin tin or line with papers. For jumbo muffins, prepare a 6-cup jumbo tin.
Measure accurately: Spoon and level flour and cocoa. Sift cocoa to prevent bitter lumps.
Use room-temp eggs and buttermilk for easier blending and better rise.

Mix the Batter

Whisk dry: In a large bowl, whisk flour, cocoa, granulated sugar, brown sugar, baking powder, baking soda, salt, and espresso powder until evenly combined.
Whisk wet: In a separate bowl, whisk buttermilk, oil, eggs, and vanilla until smooth.
Combine: Pour wet into dry. Stir with a spatula just until streaky. Do not fully mix yet.
Add hot water: Stream in hot water and gently fold until the batter looks thick, glossy, and slightly lumpy. Small lumps are fine.
Fold in chips: Stir in most of the chocolate chips, holding back a small handful for the tops.

Portion and Bake

Fill generously: Fill each cup almost to the top (about 3/4 to heaping full). Sprinkle reserved chips on top.
Start hot: Bake at 425°F for 5–7 minutes to boost oven spring.
Reduce heat: Without opening the door, reduce to 350°F (177°C) and continue baking:
- Standard muffins: 13–16 minutes more
- Jumbo muffins: 18–22 minutes more
Check doneness: A tester should come out with a few moist crumbs, not wet batter. Tops should look set and slightly glossy.
Cool properly: Rest in the pan 5 minutes, then transfer to a rack. This keeps bottoms from steaming.

Pro Tips for Tall Domes

Don’t overmix: Overworking gluten makes tough muffins and flat tops.
Thick batter wins: The batter should mound in the scoop. Add 1–2 tablespoons flour if it looks runny.
Use a scoop: A large cookie scoop gives uniform size and even baking.
Rest the batter (optional): A 20-minute rest lets flour hydrate and improves rise.

How to Store These Chocolate Muffins

Room temperature: Store cooled muffins in an airtight container with a paper towel at the bottom for 2–3 days.
Freeze: Wrap each muffin and place in a freezer bag for up to 3 months. Rewarm in the microwave for 20–30 seconds or in a 300°F oven for 8–10 minutes.
Avoid the fridge: Refrigeration dries muffins. Freeze instead if you need longer storage.

Why You’ll Love Baking This Copycat Version

Same bakery vibe: Big tops, rich chocolate, and melty chips without leaving home.
Budget-friendly: Pantry staples beat store prices, especially for jumbo muffins.
Customizable: Adjust sweetness, cocoa intensity, and chip type to your taste.
Make-ahead friendly: Freeze beautifully and taste fresh when reheated.

Common Mistakes to Avoid

Overmixing the batter: Leads to dense muffins and tunnels. Fold gently.
Skipping the temperature change: You’ll miss the signature muffin dome.
Underfilling the cups: Fill high for bakery-style size and shape.
Using cold wet ingredients: Cold batter rises less and bakes unevenly.
Overbaking: Dry muffins lose that Costco-level richness. Pull when crumbs cling to the tester.

Flavor Twists to Try

Triple chocolate: Use a mix of dark, milk, and white chips.
Chocolate orange: Add 1 tablespoon orange zest and swap vanilla for 1 teaspoon orange extract.
Mocha muffins: Increase espresso powder to 2 teaspoons and add mini chips.
Salted double chocolate: Sprinkle flaky sea salt on tops right before baking.
Chocolate peanut butter: Fold in peanut butter chips or swirl 1/3 cup warmed peanut butter into the batter.
Hidden veggie: Add 1/2 cup finely shredded zucchini; blot well to remove excess moisture.

FAQ

Can I make these as jumbo muffins?

Yes. Fill jumbo cups to the top, start at 425°F for 7–8 minutes, then finish at 350°F for 18–22 minutes. Aim for a few moist crumbs on the tester.

Which cocoa powder works best?

Use natural unsweetened cocoa for classic flavor. For deeper color and a bakery-style look, use half natural and half Dutch-process. Keep baking soda in for rise.

Can I cut the sugar?

You can reduce sugar by 2–4 tablespoons without hurting texture. Expect a slightly less tender crumb and darker chocolate notes.

Why add hot water?

Hot water blooms the cocoa so the chocolate flavor tastes fuller. It also loosens the batter for a softer crumb.

How do I prevent chocolate chips from sinking?

Toss chips with a teaspoon of the dry mix before folding in, and keep the batter thick. Topping each muffin with extra chips also ensures chocolate on top.

Can I mix by hand?

Absolutely. A whisk and spatula work best here and help avoid overmixing.

How long should I cool the muffins?

Cool 5 minutes in the pan, then move to a rack to finish. This keeps the bottoms from getting soggy.

Conclusion

With the right mixing method, a hot-to-cool bake strategy, and plenty of chocolate, you can make copycat Costco chocolate muffins any day of the week. They rise tall, stay moist, and taste just like the bakery case—maybe even better fresh from your oven. Bake a batch now, stash a few in the freezer, and treat yourself to chocolate perfection whenever the craving hits.

Copycat Costco Chocolate Muffins Recipe

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Ingredients

Instructions

Preheat to 425°F (218°C). Grease a 12-cup muffin tin or line with papers. For jumbo muffins, prepare a 6-cup jumbo tin.
Measure accurately: Spoon and level flour and cocoa. Sift cocoa to prevent bitter lumps.
Use room-temp eggs and buttermilk for easier blending and better rise.
Whisk dry: In a large bowl, whisk flour, cocoa, granulated sugar, brown sugar, baking powder, baking soda, salt, and espresso powder until evenly combined.
Whisk wet: In a separate bowl, whisk buttermilk, oil, eggs, and vanilla until smooth.
Combine: Pour wet into dry. Stir with a spatula just until streaky. Do not fully mix yet.
Add hot water: Stream in hot water and gently fold until the batter looks thick, glossy, and slightly lumpy. Small lumps are fine.
Fold in chips: Stir in most of the chocolate chips, holding back a small handful for the tops.
Fill generously: Fill each cup almost to the top (about 3/4 to heaping full). Sprinkle reserved chips on top.
Start hot: Bake at 425°F for 5–7 minutes to boost oven spring.
Reduce heat: Without opening the door, reduce to 350°F (177°C) and continue baking: Standard muffins: 13–16 minutes more
Jumbo muffins: 18–22 minutes more
Check doneness: A tester should come out with a few moist crumbs, not wet batter. Tops should look set and slightly glossy.
Cool properly: Rest in the pan 5 minutes, then transfer to a rack. This keeps bottoms from steaming.
Don’t overmix: Overworking gluten makes tough muffins and flat tops.
Thick batter wins: The batter should mound in the scoop. Add 1–2 tablespoons flour if it looks runny.
Use a scoop: A large cookie scoop gives uniform size and even baking.
Rest the batter (optional): A 20-minute rest lets flour hydrate and improves rise.

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