One Bowl Chocolate Cake with Fudgy Frosting

When the craving hits or a birthday sneaks up on you, this one bowl chocolate cake is the recipe to reach for. It is mixed by hand in a single bowl, bakes up incredibly moist and tender, and tastes deeply of chocolate thanks to cocoa powder and a cup of hot coffee.

In this post I explain why such a simple batter turns out so well, which cocoa to buy, how to mix and bake it, and how to make a quick, creamy chocolate frosting to spread on top. You will also find tips, variations, a troubleshooting table and storage advice. The full printable recipe card is waiting at the bottom of the post.

Why This One Bowl Chocolate Cake Works

Most cakes ask you to cream butter and sugar, alternate wet and dry ingredients and wash a stack of bowls. This easy chocolate cake skips all that. Everything goes into one large bowl, gets whisked together and pours straight into the pan.

• Oil for moisture. Oil keeps the crumb soft and tender for days, even after a night in the refrigerator.
• Buttermilk for tenderness. Its gentle acidity reacts with the baking soda for a fine, even rise and adds a subtle tang.
• Hot coffee for flavor. Hot liquid blooms the cocoa powder, releasing a deeper chocolate flavor. The cake does not taste like coffee.
• A thin batter. The batter is very loose, which is exactly what creates the plush, moist texture.
• A sheet pan format. Baking in a 9×13-inch pan means no layers to level or stack, and you frost it right in the pan.

The result is a homemade chocolate cake with a rich, dark crumb that tastes like it took far more effort than it did. It is the cake I make for school parties, potlucks and any day that needs a little chocolate.

Cleanup is just as easy. With only one bowl, one whisk and one pan, the kitchen is tidy again before the cake even comes out of the oven.

Ingredients You Will Need

Everything here is a pantry staple. The quality of your cocoa powder matters most, since it carries all of the chocolate flavor.

• All-purpose flour: Spoon and level it for an accurate measurement.
• Granulated sugar: Sweetens the cake and helps keep it moist.
• Unsweetened cocoa powder: Natural cocoa works best with the baking soda in this recipe. Dutch-process cocoa also works and gives a darker, smoother flavor.
• Baking soda and baking powder: Together they give a tall, even rise.
• Salt: Brings out the chocolate flavor.
• Eggs: Two large eggs, at room temperature.
• Buttermilk: Full-fat or low-fat both work. No buttermilk? Stir 1 tablespoon of lemon juice or white vinegar into 1 cup of milk and let it sit for 5 minutes.
• Vegetable oil: Any neutral oil, such as canola or vegetable.
• Vanilla extract: Rounds out the chocolate.
• Hot coffee or hot water: Freshly brewed coffee gives the richest flavor, but hot water works if you prefer.

For the frosting you will need softened butter, cocoa powder, powdered sugar, a splash of milk, vanilla and a pinch of salt. It comes together in about 5 minutes while the cake cools.

How to Make One Bowl Chocolate Cake

You will need one large bowl, a whisk and a spatula for the cake. Use a hand mixer for the frosting if you have one, though a sturdy wooden spoon also works.

1. Prepare the pan. Heat the oven to 350°F (175°C). Grease a 9×13-inch metal baking pan and dust it with cocoa powder, or line it with parchment.
2. Whisk the dry ingredients. In a large bowl, whisk the flour, sugar, cocoa powder, baking soda, baking powder and salt until evenly combined and free of lumps.
3. Add the wet ingredients. Add the eggs, buttermilk, oil and vanilla to the same bowl and whisk for about 1 minute, until thick and smooth.
4. Add the hot coffee. Slowly pour in the hot coffee while whisking. The batter will be very thin. That is exactly right.
5. Bake. Pour the batter into the pan and bake for 32 to 38 minutes, until a toothpick inserted in the center comes out clean or with a few moist crumbs and the top springs back when lightly pressed.
6. Cool. Let the cake cool completely in the pan on a wire rack, about 1 hour.
7. Make the frosting. Beat the softened butter until creamy. Add the cocoa powder, powdered sugar, milk, vanilla and salt, and beat until smooth and fluffy, adding a little more milk if needed.
8. Frost and serve. Spread the frosting over the cooled cake in big swoops, then cut into squares.

Do not worry when the batter looks like chocolate soup. A thin batter is the reason this cake bakes up so soft and moist.

Tips for the Best Easy Chocolate Cake

• Use a metal pan for even baking. Glass pans bake slower in the center, so add a few minutes and lower the heat to 325°F (165°C).
• Do not overbake. Start checking at 30 minutes, because the cake keeps cooking a little as it cools.
• Make sure the coffee is hot, not boiling, so it blooms the cocoa without scrambling the eggs.
• Bring the eggs and buttermilk to room temperature so they blend smoothly into the batter.
• Let the cake cool completely before frosting, or the frosting will melt and slide.
• For tidy squares, chill the frosted cake for 20 minutes and wipe the knife between cuts.

Chocolate lovers should also try my fudgy brownies with a crackly top, a rich molten chocolate lava cake, or an easy German chocolate dump cake. For more ideas, browse my dessert recipe collection.

Layer Cake and Cupcake Options

This batter is as flexible as it is easy. For a classic birthday layer cake, divide it between two greased and parchment-lined 9-inch round pans and bake for 28 to 34 minutes. Cool completely, then double the frosting recipe to fill and cover the layers.

For cupcakes, fill lined muffin cups about two-thirds full and bake for 18 to 22 minutes. You will get about 24 cupcakes. For a Bundt cake, grease the pan very well and bake for 40 to 50 minutes, then finish with a simple chocolate glaze instead of frosting.

Because the batter is thin, fill pans and liners carefully using a measuring cup with a spout. It makes the job much tidier and helps every cupcake bake to the same size.

Frosting and Topping Ideas

The fudgy chocolate frosting in the recipe card is quick and classic, but this cake pairs well with all sorts of toppings.

• Chocolate ganache: Pour 1 cup of hot heavy cream over 8 ounces of chopped semisweet chocolate, let it sit 5 minutes and stir until glossy.
• Peanut butter frosting: Beat 1/2 cup each of softened butter and creamy peanut butter with 2 cups powdered sugar and a splash of milk.
• Vanilla buttercream: A classic choice for birthdays, especially with rainbow sprinkles.
• Whipped cream and berries: A lighter option for summer gatherings.
• Simple dusting: Skip the frosting and dust with powdered sugar for an afternoon snack cake.

Whichever topping you choose, make it while the cake cools so everything is ready at the same time. A thick frosting is best spread with an offset spatula in loose swirls, which hides any small cracks on the surface and looks wonderfully homemade. Add sprinkles right away, before the frosting sets, so they stick.

Easy Variations

• Mocha cake: Add 1 teaspoon of instant espresso powder to the dry ingredients and to the frosting.
• Chocolate chip cake: Sprinkle 1 cup of mini chocolate chips over the batter right before baking.
• Mint chocolate cake: Add 1/2 teaspoon of peppermint extract to the frosting and top with chopped mint chocolates.
• Orange chocolate cake: Whisk the zest of 1 orange into the batter for a bright, citrusy twist.
• Halloween cake: Top the frosted cake with candy eyes, orange sprinkles and gummy worms for a festive October party.

Common Mistakes and How to Fix Them

Make Ahead, Storage and Freezing

Thanks to the oil, this cake stays moist for days. Cover the frosted cake and keep it at room temperature for up to 2 days, or refrigerate it for up to 5 days. Bring chilled slices back to room temperature for 20 minutes before serving for the softest texture. The batter contains raw eggs and raw flour, so save the bowl licking for the frosting; the FDA advice on raw dough and batter explains why.

To make ahead, bake the cake up to 2 days early and keep it tightly covered, then frost on the day you serve. You can also freeze the unfrosted cake, wrapped in plastic wrap and foil, for up to 3 months. Thaw it in the wrapping on the counter so any condensation forms on the wrap instead of the cake.

Frequently Asked Questions

Ready to bake? Here is the full printable one bowl chocolate cake recipe with exact measurements, baking times and estimated nutrition.

One Bowl Chocolate Cake

A moist, deeply chocolatey sheet cake mixed by hand in one bowl with cocoa, buttermilk and hot coffee, topped with creamy chocolate frosting.

Print Recipe Pin Recipe

Prep Time 15 minutes mins

Cook Time 35 minutes mins

Cooling 1 hour hr

Total Time 1 hour hr 50 minutes mins

Servings: 16 pieces

Course: Dessert

Cuisine: American

Calories: 370

Ingredients Method Notes

Ingredients

  

Cake

• 1 3/4 cups all-purpose flour spooned and leveled (220 g)
• 1 3/4 cups granulated sugar (350 g)
• 3/4 cup unsweetened cocoa powder sifted (65 g)
• 1 1/2 teaspoons baking soda
• 1 teaspoon baking powder
• 1 teaspoon fine salt
• 2 large eggs room temperature
• 1 cup buttermilk room temperature (240 ml)
• 1/2 cup vegetable oil (120 ml)
• 2 teaspoons pure vanilla extract
• 1 cup hot brewed coffee or hot water (240 ml)

Chocolate frosting

• 1/2 cup unsalted butter softened (113 g)
• 2/3 cup unsweetened cocoa powder sifted (55 g)
• 3 cups powdered sugar sifted (360 g)
• 1/3 cup milk plus more as needed (80 ml)
• 1 teaspoon pure vanilla extract
• 1 pinch fine salt

Method

 

Make the cake

1. Heat the oven to 350°F (175°C). Grease a 9×13-inch metal pan and dust with cocoa powder or line with parchment.
2. In a large bowl, whisk the flour, sugar, cocoa powder, baking soda, baking powder and salt until combined.
3. Add the eggs, buttermilk, oil and vanilla and whisk for 1 minute until smooth.
4. Slowly whisk in the hot coffee. The batter will be thin.
5. Pour into the pan and bake for 32 to 38 minutes, until a toothpick in the center comes out clean or with a few moist crumbs.
6. Cool completely in the pan on a wire rack, about 1 hour.

Make the frosting

1. Beat the butter until creamy. Add the cocoa, powdered sugar, milk, vanilla and salt and beat until smooth and fluffy, adding milk a teaspoon at a time if needed.
2. Spread the frosting over the cooled cake and cut into 16 squares.

Notes

Layer cake: Bake in two 9-inch rounds for 28 to 34 minutes and double the frosting.

Storage: Keep covered at room temperature for 2 days or refrigerated for 5 days. Freeze unfrosted for up to 3 months.

Nutrition is an estimate per piece with frosting.

I hope this one bowl chocolate cake becomes your go-to for birthdays, bake sales and lazy weekend cravings. If you make it, please leave a comment and a star rating below and tell me which frosting you chose. Happy baking, friends. Chef Amber