Experience the classic flavor pairing of chocolate and orange in its most luxurious form. This cake features two exceptionally moist and tender chocolate layers, deeply infused with fresh orange zest and a hint of orange liqueur or extract. It’s enveloped in a rich, silky chocolate buttercream that’s been perfectly balanced with the same bright citrus notes.
The result is a sophisticated, beautifully balanced dessert where neither flavor overpowers the other, making it ideal for birthdays, holidays, or any special gathering that calls for a show-stopping cake.
The Synergy of Chocolate and Orange
The magic of this combination is more than just taste—it’s chemistry. The essential oils in orange zest contain aromatic compounds that accentuate the fruity, floral notes already present in high-quality cocoa.
To infuse the cake itself, we use the creaming method, rubbing the orange zest into the granulated sugar. This process (called “maceration”) releases the zest’s fragrant oils directly into the sugar, ensuring the orange flavor is baked into every bite.
For the frosting, we reinforce the citrus with a concentrated orange reduction or liqueur, which blends seamlessly into the buttercream without adding unwanted moisture. Using Dutch-processed cocoa powder provides a deeper, less acidic chocolate flavor that pairs more harmoniously with the bright, slightly acidic orange.
Ingredients
For the Chocolate Orange Cake Layers:
- 2 cups (400g) granulated sugar
- Zest of 2 large oranges
- 1 ¾ cups (219g) all-purpose flour
- ¾ cup (75g) unsweetened Dutch-processed cocoa powder
- 2 teaspoons baking soda
- 1 teaspoon baking powder
- 1 teaspoon fine sea salt
- 2 large eggs, room temperature
- 1 cup (240ml) buttermilk, room temperature
- ½ cup (120ml) vegetable oil
- 2 teaspoons pure vanilla extract
- 1 cup (240ml) hot strong brewed coffee or hot water
For the Chocolate Orange Buttercream:
- 1 ½ cups (3 sticks / 340g) unsalted butter, softened
- 1 cup (95g) unsweetened cocoa powder, sifted
- 5 cups (600g) powdered sugar, sifted
- ⅓ cup (80ml) orange juice reduction* or ¼ cup Grand Marnier/Cointreau
- 2 teaspoons vanilla extract
- Pinch of salt
- 2-3 tablespoons heavy cream or milk, as needed
Reduction: Simmer ¾ cup orange juice until reduced by half to ⅓ cup. Cool completely.
For Garnish: Candied orange peel, chocolate curls, fresh orange slices, or edible gold leaf.
Instructions
1. The Zest-Infused Sugar: In a small bowl, combine the granulated sugar and orange zest. Use your fingertips to rub the zest into the sugar for a full minute until the sugar is fragrant, moist, and pale orange in color.
2. The Smooth Cake Batter: Preheat oven to 350°F (175°C). Grease and line two 9-inch round cake pans. In the bowl of a stand mixer, sift together flour, cocoa powder, baking soda, baking powder, and salt. Add the orange sugar and whisk to combine.
On medium speed, add eggs, buttermilk, oil, and vanilla. Beat for 2 minutes. Reduce speed to low and carefully pour in the hot coffee. Mix just until combined; the batter will be thin.
3. The Baked & Cooled Cake Layers: Divide batter evenly between prepared pans. Bake for 30-35 minutes, until a toothpick inserted in the center comes out clean. Let cakes cool in pans for 10 minutes, then turn out onto a wire rack to cool completely. Level the tops if necessary.
4. The Fluffy Chocolate Orange Buttercream: In a stand mixer fitted with a paddle attachment, beat the softened butter on medium-high speed until very pale and creamy, about 5 minutes. With mixer on low, add the sifted cocoa powder and mix until combined.
Gradually add the sifted powdered sugar and salt. Once incorporated, add the cooled orange reduction (or liqueur) and vanilla. Beat on medium-high for 3-4 minutes until very light and fluffy. If too thick, add heavy cream a tablespoon at a time.
5. The Frosted & Finished Layer Cake: Place one cake layer on a serving plate. Spread with a generous layer of buttercream. Top with the second layer. Apply a thin “crumb coat” of frosting over the entire cake and chill for 15 minutes.
Apply the final, thick layer of frosting, smoothing the sides and top. Decorate with garnishes. For best flavor, let the cake sit at room temperature for at least an hour before slicing.
Pro-Tips for a Perfect Pairing
- Macerate the Zest: Don’t skip rubbing the zest into the sugar—it’s the secret to a deeply orange-flavored cake.
- Use Room Temperature Ingredients: This ensures proper emulsification for a tender, even crumb.
- Hot Liquid Blooms Cocoa: The hot coffee (or water) intensifies the chocolate flavor without making the cake taste like coffee.
- Cool Cakes Completely: Warm cakes will melt the frosting. Wrap and chill layers if needed.
- Reduce Orange Juice: If not using liqueur, reducing orange juice concentrates flavor and removes water that could thin the frosting.
- Sift Dry Ingredients: This is crucial for a smooth frosting without lumps of cocoa or powdered sugar.
- Make Ahead: Unfrosted cake layers can be wrapped and frozen for up to a month. Thaw before frosting. The frosted cake keeps at cool room temperature for 2 days or in the fridge for up to 5 days; bring to room temperature to serve.
