Buttermilk chocolate cake

Buttermilk Chocolate Cake – a rich, fudgy, and super moist homemade cake topped with a glossy chocolate frosting. Made in just one bowl with simple ingredients, it’s perfect for birthdays, class parties, family gatherings, or any time you need a quick and indulgent chocolate fix. This old-fashioned cake combines ease with decadent flavor that everyone will love.

Love More Chocolate Desserts ? Try My Chocolate Cherry Upside Down Cake or this Chocolate Lava Cookies next.

Why You’ll Love This Recipe

Moist, fluffy, and stays fresh for days—rare for homemade cakes. Even professional bakers will ask for the recipe after tasting it. Simple store-bought buttermilk keeps the flavor classic and perfect, without any tang, making it an effortless crowd-pleaser every time.

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Ingredients You’ll Need

For the Cake:

• 2 cups all-purpose flour (240 g) – regular flour, nothing fancy
• 2 cups granulated sugar (400 g) – white sugar
• ½ cup unsweetened cocoa powder (40 g) – Hershey’s works fine
• 1½ teaspoons baking soda – check expiration date
• 1 teaspoon baking powder – also check this
• ¼ teaspoon salt – table salt is fine
• 2 large eggs, room temperature – leave them out for an hour
• ½ cup melted butter (118 ml) – microwave 30 seconds
• ½ cup canola oil (118 ml) – vegetable oil works too
• 1 cup buttermilk, room temperature (237 ml) – the magic ingredient
• 1 cup hot water (237 ml) – from the tap, really hot but not boiling

For the Frosting:

• ¾ cup unsalted butter (170 g) – stick and a half
• ½ cup unsweetened cocoa powder (40 g) – same as before
• ⅓ cup buttermilk, room temperature (79 ml) – leftover from cake
• 1 teaspoon vanilla extract – the good stuff if you have it
• 2½ to 3 cups powdered sugar (300-360 g)

Smart Substitutions: No buttermilk? Put a tablespoon of lemon juice in regular milk, stir, wait 5 minutes. Tastes exactly the same. Sarah down the street uses oat milk and says it works great.

Why These Ingredients Work

Buttermilk makes everything light and fluffy because science – the acid reacts with baking soda. Also keeps it from going stale in two days like most cakes.

Butter and oil together because butter tastes better but oil keeps it moist longer. Hot water makes the cocoa taste more chocolate-y. My mom learned this working at a restaurant in college.

Essential Tools and Equipment

Basic stuff you probably have:

• Big bowl – biggest one you own
• Whisk – fork works if you don’t have one
• 9×13 pan – metal or glass, doesn’t matter
• Parchment paper – saves your sanity later
• Medium pot – for frosting
• Cooling rack – or just leave it in the pan
• Spatula – anything that spreads frosting

How To Make Buttermilk Chocolate Cake

Step 1: Get Ready to Bake

Oven to 350°F. Grease the pan, put parchment in it. Don’t skip parchment paper – trust me on this one.

Step 2: Mix the Dry Stuff

Dump flour, cocoa, sugar, baking soda, baking powder, salt in the bowl. Whisk it around. Break up any cocoa clumps with your fingers if you see them.

Step 3: Add Wet Stuff

Pour in oil, melted butter, eggs, buttermilk. Mix until it looks combined. Doesn’t need to be perfect.

Step 4: The Magic Water

Add the hot water while stirring. Batter gets really thin and looks wrong but that’s normal. Pour in the pan.

Step 5: Bake

30-35 minutes. Stick a toothpick in the middle – should have a few crumbs on it. If it’s browning too fast, cover with foil.

Step 6: Cool It

Wait 15-20 minutes then lift out with parchment. Has to be completely cool or frosting melts everywhere.

Step 7: Frosting Time

Melt butter in the pot. Add cocoa, stir for a minute. Take off heat. Add buttermilk, vanilla, powdered sugar. Whisk until smooth. Spread on cake.

You Must Know

Everything room temp. Cold stuff doesn’t mix right and you get dense cake. I set eggs and buttermilk out when I start dinner.

Sift the cocoa. Those lumps taste bitter and gross. Learned this the hard way at my mother-in-law’s birthday.

Pro Tips & Cooking Hacks

• Test your baking soda – drop some in vinegar, should fizz like crazy
• Don’t overmix – once water goes in, just stir until smooth
• Fix runny frosting – add more powdered sugar bit by bit
• Fix thick frosting – add buttermilk teaspoon by teaspoon
• Rotate pan halfway through if your oven cooks unevenly like mine

Flavor Variations to Keep Things Exciting

Same recipe, different flavors:

Mint: Add 1 tsp peppermint extract plus ½ cup mini chocolate chips

Coffee: Mix 2 tbsp instant coffee in the hot water first

Orange: Add 2 tbsp orange zest to batter, 1 tsp orange extract to frosting

Spicy: Add ½ tsp cinnamon and pinch of cayenne to dry ingredients

Make-Ahead Options for Busy Bakers

Make cake without frosting up to 2 days ahead, wrap tight, leave on counter. Frosting keeps in fridge overnight – just let it warm up before using.

Freeze unfrosted cake wrapped in plastic then foil for 2 months. Thaw completely before frosting. With frosting, keeps 4 days on counter or week in fridge.

Recipe Notes & Baker’s Tips

Thin batter freaks people out but it makes the moistest cake ever. Don’t add more flour.

High altitude (over 3000 feet): use 1 tsp baking soda, add 2 tbsp flour, bake 5-10 minutes less. My sister lives in Denver and this works for her.

Serving Suggestions

Honestly it’s perfect plain but these make it fancy:

• Vanilla ice cream and berries
• Dust with powdered sugar
• Whipped cream and caramel sauce
• Glass of cold milk

Good for birthdays, bake sales, making up with your spouse, or Wednesday because you want cake.

How to Store Your Buttermilk Chocolate Cake

Counter covered: 4 days. Fridge: week. If you put it in the fridge, leave it out 30 minutes before serving.

Freeze: Wrap unfrosted cake in plastic then foil, 2 months max. Thaw before frosting.

Reheat: Microwave slices 15 seconds for that just-baked taste.

Allergy Information

Has eggs, dairy, wheat. Use 1:1 gluten-free flour for gluten-free. Plant milk plus lemon juice for dairy-free. Never tried egg substitutes but probably works.

Questions I Get Asked A Lot

Can I make this in round cake pans instead?

Absolutely! Divide the batter between two greased 9-inch round pans and bake for 25-30 minutes. Perfect for layer cakes!

My frosting turned out grainy – what happened?

This usually means the powdered sugar wasn’t sifted or was added too quickly. Always sift first and add gradually while whisking.

Can I use Dutch-processed cocoa powder?

Yes! Dutch-processed cocoa will give you a richer, less acidic flavor. The recipe works beautifully with either type.

💬 Made this recipe? Tell me how it went! Did you try any of the flavor variations?