Enjoy 2 cakes in 1 with this buttery-rich marble loaf cake! Baking a cake in a loaf pan means easy prep and minimal decorating—without sacrificing taste. The chocolate batter is made from the vanilla, so you don’t have to prepare 2 separate batters. And don’t forget the 2-ingredient glossy chocolate ganache topping!
I originally published this recipe in 2022 but recently revisited it and retested it to see if I could improve it. I always like to continue to work on recipes, including ones that have been published and may not have the best reviews.
In the case of this marble loaf cake recipe, some reviewers reported that it was dry or dense, not tall enough, and/or it lacked flavor. When I see a pattern of reviews with concerns over the same thing, my team and I will revisit the recipe and try making various tweaks until we are all confident that we have fixed the issues that readers have been having.
After going back to the test kitchen, I’m proud to announce this marble loaf cake is better than ever! You’ll notice a few ingredient tweaks in the updated recipe, including adding a little baking soda and another egg for extra lift; and we’re swapping the whole milk and sour cream for buttermilk, which adds extra moisture to the cake crumb. Buttermilk saves the day, yet again. The updated recipe is below.
This New & Improved Marble Loaf Cake Has:
- A lighter, fluffier, more moist texture
- More pure cocoa flavor
- The same rich dark chocolate ganache topping.
If you love homemade marble cake, but don’t need a towering giant with layers of sweet frosting that makes a ton of servings, or if you don’t feel like making the effort to decorate and assemble a layer cake, this easy yet impressive dessert is for you!
(But also, if you DO want that sort of marble cake, try this 3-layer zebra cake, or the 2-layer marble cake in my cookbook, Sally’s Baking 101.)
Key Ingredients You Need for Marble Loaf Cake:
Let me explain some of the most important ingredients you need and why:
- Creamed Butter & Sugar: Like most cake recipes, the wet ingredients start with room-temperature butter and granulated sugar to create a fluffy base. Learn why this step is important in this post on how to cream butter and sugar.
- Buttermilk: A key moisture provider that makes a big difference in the texture of this cake. We strongly recommend using store-bought buttermilk (either full-fat or low-fat), but in a pinch, you can make your own buttermilk substitute with whole milk.
- Cocoa Powder: You need cocoa powder to make your chocolate batter. Remember this post on Dutch-process vs. natural cocoa powder? In testing this marble loaf cake, we found that using Dutch-processed cocoa made for the best, smoothest-tasting chocolate flavor. I usually use this brand (not working with them, just a fan of the product!).
- Espresso Powder: Just like in chocolate cake, we use espresso powder to enhance and deepen the chocolate flavor—it doesn’t taste like coffee at all. You can find espresso powder in the coffee aisle at your grocery store or online.
Made From 1 Batter
The cake batter follows a simple, familiar process. Whisk the dry ingredients together, then, in a separate bowl, use a mixer to cream the butter and sugar together. Beat in the eggs and vanilla. Pour in the dry ingredients and then, with the mixer running, slowly add the buttermilk.
The chocolate cake is made from the vanilla batter, so you don’t have to prepare two completely separate batters. It’s how I prepare the batters for this zebra marble cake, too. YAY!
Divide the batter into two bowls and add cocoa powder and espresso powder to one. Since we’re adding these dry and bitter ingredients to the chocolate batter, it will dry out the cake. A little warm buttermilk solves that problem. (Warm liquid helps the cocoa and espresso powders bloom/dissolve.) Both the vanilla cake and chocolate cake are so moist.
We did it!
Here’s Exactly How to Swirl the Batters Together
- Spread a thin layer of the plain vanilla batter on the bottom of the pan.
- Layer spoonfuls of each batter on top. Cover bottom vanilla layer with a few spoonfuls of the chocolate batter, then a few spoonfuls of the vanilla batter, then more chocolate batter, then more vanilla batter, and so on until all of the cake batter is used.
- Gently shimmy the pan to level out the batters.
- Using a knife, make rounded horizontal zig-zags from one side of the pan to the other, and then make rounded vertical zig-zags from the top to the bottom. You can also use a toothpick to get a little more intricate with the marbling on top.
2-Ingredient Chocolate Ganache Topping
To top the cake, let’s turn to the wonderful dessert concoction known as ganache. Chocolate ganache is typically made with 1:1 semi-sweet chocolate and heavy cream or heavy whipping cream, but for this cake I wanted a thicker-style ganache so I reduced the amount of cream. Because there’s less liquid, it’s best to melt these two ingredients together rather than pour the warm cream over the chocolate like we usually do.
Let the ganache thicken for 20 minutes and then pour and spread it over your cake. It’s glorious! It will set into a soft fudge-like consistency after a couple hours.
Marble loaf cake has built-in beauty with no complicated assembly or decorating skills required. We can all appreciate that!
I hope you enjoy this new and improved version.
Description
You’ll love this buttery and moist marble loaf cake because it’s beautiful and impressive without any fancy decorating skills required. The chocolate batter is made from the vanilla, so you don’t have to prepare 2 separate cake batters from scratch.
Cake
Chocolate Ganache Topping
- Preheat the oven to 350°F (177°C) and generously grease a 9×5-inch loaf pan.
- Make the cake batter: In a medium bowl, whisk together the flour, baking powder, baking soda, and salt. Set aside.
- Using a handheld or stand mixer fitted with a paddle attachment, beat the butter and sugar together on medium speed until light and fluffy, about 5 minutes. Scrape down the sides and bottom of the bowl with a silicone spatula as needed. Add the eggs and vanilla and beat on high speed for 1 minute. The mixture may look a bit curdled at this point—that’s OK! Scrape down the sides and bottom of the bowl as needed. Pour the flour mixture into the wet ingredients. Turn the mixer to low speed and as the mixer runs, slowly pour in 3/4 cup + 2 Tbsp (210g/ml) of the buttermilk (reserve remaining 2 Tbsp (30g/ml)). Beat on low speed just until combined. Do not over-mix. You may need to whisk it all by hand to make sure there are no large lumps at the bottom of the bowl. The batter will be slightly thick.
- You’ll have about 3–3.5 cups of batter. Transfer a little less than half (just eyeball it, doesn’t need to be perfect) of the batter to another bowl. Warm the reserved 2 Tablespoons of buttermilk in the microwave for 10–15 seconds. Stir the espresso powder into the warm buttermilk until dissolved, then pour it into the bowl that contains slightly less than half of the batter. Sprinkle the cocoa powder over the top, then stir, whisk, or beat on low speed until combined.
- Layer and swirl the batters: Spread a thin layer of the plain vanilla batter in the bottom of your prepared loaf pan. Now you will layer spoonfuls of each batter on top—cover bottom vanilla layer with a few spoonfuls of the chocolate batter, then a few spoonfuls of the vanilla batter, then more chocolate batter, then more vanilla batter, and so on until all of the cake batter is used. Gently shimmy the pan to level out the batters. Using a knife, make rounded horizontal zig-zags from one side of the pan to the other, and then make rounded vertical zig-zags from the top to the bottom.
- Bake for 65–75 minutes, or until a toothpick inserted in the center comes out clean. That time is a guideline—all ovens differ, so keep a close eye on the cake after 55 minutes. If the cake is browning too quickly on top before the center is fully baked, loosely tent a sheet of aluminum foil over top of the pan. (I always tent with foil after 30 minutes.)
- Cool the cake in the pan set on a cooling rack for 30 minutes, then remove the cake from the pan and place it directly on the rack.
- As the cake cools, make the ganache topping: Place the chocolate and cream in a medium heat-safe bowl set over a medium saucepan of simmering water. (Or use a double boiler if you have one.) Do not let the bottom of the bowl touch the water. Stir frequently until chocolate has melted and ganache is smooth. Remove from heat and set aside at room temperature for 20 minutes or until slightly thickened.
- Drizzle or spread topping on cake. Cake is delicious sliced and served slightly warm. The topping sets into a fudge-like consistency after several hours.
- Cover leftovers tightly and store cake (with or without topping) at room temperature for up to 3 days or in the refrigerator for up to 1 week.
Notes
- Freezing Instructions: Topped or plain cake freezes well for up to 3 months. Wrap the cooled cake in a layer of plastic wrap, followed by a layer of aluminum foil. Thaw overnight in the refrigerator, then bring to room temperature or serve cold. See How to Freeze Cakes for more information.
- Special Tools (affiliate links): Dutch-Process Cocoa | 9×5-inch Loaf Pan | Glass Mixing Bowl | Whisk | Electric Mixer (Handheld or Stand) | Cooling Rack | Double Boiler
- Room-Temperature Ingredients: All refrigerated items should be at room temperature so the batter mixes together easily and evenly. Read more about room-temperature ingredients in baking.
- Buttermilk: If you don’t have buttermilk, you can make a DIY buttermilk substitute. Add 2 teaspoons of white vinegar or lemon juice to a liquid measuring cup. Then add enough whole milk to the same measuring cup until it reaches 1 cup. (In a pinch, lower-fat or nondairy milks work for this soured milk, but the cake won’t taste as moist or rich.) Stir it and let sit for 5 minutes. The homemade “buttermilk” will be somewhat curdled and ready to use in the recipe.
- Espresso Powder: Espresso powder will not make the cake taste like coffee. Instead, it deepens the chocolate flavor. You can use the same amount of instant coffee (the powder—not coffee grounds) instead of espresso powder if desired.
- Chocolate: Ganache will only set if the correct chocolate is used. You can use high-quality chocolate chips if needed (I prefer Ghirardelli or Guittard semi-sweet chocolate chips), but I recommend using pure chocolate baking bars, in either semi-sweet or bittersweet. You can find them right next to the chocolate chips in the baking aisle. They are sold in 4-ounce (113g) bars. I like Bakers or Ghirardelli brands.
- Updated in 2025: The recipe above is new and improved. If you prefer to make the original version, expect a denser, flatter loaf. To make that older version, increase the baking powder to 1 and 1/2 teaspoons and skip the baking soda. Reduce the butter to 1/2 cup (8 Tbsp; 113g) and sugar to 1 cup (200g). Use 2 eggs. Skip the buttermilk and replace with 1/4 cup (60g) sour cream and 2/3 cup milk (160ml), plus 2 Tbsp milk for the chocolate batter. Follow the same instructions. The bake time is around 1 hour, same oven temperature.
