Decadent Chocolate Orange Cake — Extra Moist

This super-easy chocolate orange cake is rich, moist and delightfully gooey, with bright, natural orange notes throughout.

Zesty orange peel, fresh orange juice, a touch of marmalade and orange-flavoured chocolate combine with deep cocoa and a splash of strong coffee for an indulgent, balanced flavour. The result is a tender, moist cake that improves a day or two after baking.

A small amount of coffee is added to amplify the chocolate flavour without making the cake taste like coffee.

This cake is exceptionally moist and makes an excellent centrepiece for birthdays, special occasions, or an elevated everyday dessert.

What’s to love about this recipe

• Easy to follow and reliable for both novice and experienced bakers.
• Stays moist for several days when stored properly.
• Full-bodied chocolate flavour with a natural orange lift—no artificial extract required.
• Works beautifully for celebrations as a layered birthday cake or as an everyday treat.

Key ingredient notes and substitutions

Please see the recipe card at the bottom of this post for the full ingredient list and quantities.

Cake ingredients

Buttercream ingredients

Light brown sugar

Light brown sugar adds a subtle caramel note and depth to the cake. If unavailable, regular brown sugar is a suitable substitute.

Cocoa powder

Use a good-quality unsweetened cocoa powder if possible. Dutch-processed cocoa gives a smoother, darker flavour, but standard cocoa powder will still produce excellent results.

Eggs

Bring eggs to room temperature before baking for better integration into the batter. If short on time, place eggs in warm water for 10 minutes to take the chill off.

Strong black coffee

A strong brewed coffee or a teaspoon of instant espresso dissolved in hot water will intensify the chocolate notes. The coffee flavour should be subtle, simply enhancing the chocolate.

Orange juice and zest

Freshly squeezed orange juice and the zest of one orange provide bright, natural citrus flavour. For a milder taste, reduce the zest to half an orange or omit it entirely.

Orange chocolate

Use any orange-flavoured chocolate you prefer for the buttercream. Popular chocolate options with orange flavour work well and can also be used as decorative slices or shards on the finished cake.

Marmalade

A thin layer of orange marmalade between the sponge layers adds a complementary tang and a touch of moisture. If marmalade is not to your taste, you can leave it out without compromising the cake.

Baking tins

This recipe is designed for 2 x 8-inch (20cm) round cake pans. Alternatively, use 3 x 6-inch pans to make a taller three-layer cake.

Step-by-step instructions

To make the sponges

1. Preheat the oven to 180C / 356F / gas mark 4.

2. Line the bottoms of two 20cm (8″) pans with parchment circles and lightly butter or spray the sides.

3. In a large bowl, whisk together light brown sugar, all-purpose flour, cocoa powder, baking powder, bicarbonate of soda and salt until evenly combined and free of lumps.

4. In a small bowl, beat the eggs briefly with a fork. Add eggs, sour cream, prepared coffee, orange juice, vegetable oil, vanilla extract and orange zest to the dry ingredients.

5. Using a hand mixer on low speed, mix until just combined—do not overmix. Divide batter evenly between the prepared tins (about 700g per tin if weighing) and tap the tins to remove large air bubbles.

6. Bake for approximately 35 minutes, or until a skewer inserted into the centre comes out mostly clean. A few moist crumbs are normal for this recipe. The tops should feel springy.

7. Allow the cakes to cool in their tins for 10 minutes, then loosen the edges and invert onto a wire rack. Remove the parchment and cool completely before decorating.

Make the chocolate orange buttercream

1. In a stand mixer bowl, beat softened unsalted butter with sifted icing sugar on medium-high until light and fluffy, about 5 minutes.

2. Add melted orange-flavoured chocolate and sifted cocoa powder. Beat until smooth and well combined.

3. Add orange juice, one tablespoon at a time, until the buttercream is spreadable. Adjust texture as needed.

Assembling the cake

1. Spread a thin layer of marmalade on the first sponge, then add a generous layer of buttercream. Top with the second sponge to create a sandwich.

2. Use the remaining buttercream to cover the top and sides of the cake, smoothing for a clean finish. Decorate with chocolate shavings, slices of orange chocolate, fresh orange slices or candied peel if desired.

Decoration ideas

• Candied orange peel or dehydrated orange slices for an elegant touch.
• Chocolate shavings, curls or chips to emphasize the chocolate element.
• Piping decorative buttercream details or using a chocolate ganache in place of the orange buttercream.
• Serve with lightly whipped cream on the side for added richness.

Storage

Store the cake in an airtight container in the refrigerator for up to 3–4 days. The flavours meld over time, so the cake often tastes even better after a day.

Freezing the cake

To freeze uniced sponge layers for up to three months: cool completely, wrap each layer tightly in several layers of plastic wrap to prevent freezer burn, then place in an airtight container. Thaw at room temperature for a few hours before decorating.

Top tips

Weigh your ingredients

Use a digital kitchen scale for accurate results and consistent cakes.

Scrape the bowl

Scrape the bottom and sides of the mixing bowl between mixes to ensure no dry ingredients are left unincorporated.

Even layer heights

Weigh batter into each tin for equal layers—approximately 700g per 20cm tin—so the finished cake stacks evenly.

Sift dry ingredients for smooth buttercream

Sifting icing sugar and cocoa powder prevents lumps and creates a silky buttercream that’s easy to spread and pipe.

Make frosting easier

Chill the cakes for an hour or two in the freezer before frosting; this firms them up and makes frosting simpler and neater.

Avoid a cloud of icing sugar

Start the mixer slowly when combining butter and icing sugar, or press the butter into the sugar first to reduce airborne sugar dust.

Leveling domed cakes

Invert a slightly domed cake while still warm to flatten it, or trim the dome with a serrated knife for an even surface before stacking.

FAQ