This Mary Berry Chocolate Birthday Cake is a rich and indulgent recipe, which is made with a simple, all-in-one cake batter and a luxurious chocolate butter icing. It’s a classic, foolproof recipe, perfect for a special celebration.
Mary Berry Chocolate Birthday Cake Ingredients
For the Cake:
- 275g (10 oz) plain flour
- 3 tbsp. cocoa powder
- 1½ tsp. bicarbonate of soda
- 1½ tsp. baking powder
- 215g (7½ oz) caster sugar
- 3 tbsp. golden syrup
- 3 eggs, beaten
- 225 ml (8 fl oz) sunflower oil
- 225 ml (8 fl oz) milk
For the Icing:
- 450g (1 lb) plain chocolate, broken into pieces
- 200g (7 oz) unsalted butter
For the optional Chocolate Waves:
- About 50g (2 oz) each of white and plain chocolate
How To Make Mary Berry’s Chocolate Birthday Cake
- Prep the oven and tins: Preheat the oven to 160°C/325°F/Gas Mark 3. Lightly grease two 20cm (8-inch) round sandwich tins and line the bases with non-stick baking paper.
- Mix the cake batter: Sift the flour, cocoa powder, bicarbonate of soda, and baking powder into a large bowl. Add the caster sugar and mix well. Make a well in the center of the dry ingredients and add the golden syrup, beaten eggs, sunflower oil, and milk. Beat well with a wooden spoon until you have a smooth batter.
- Bake the cakes: Pour the batter evenly into the prepared tins. Bake for about 35 minutes, until the cakes are well-risen and spring back when pressed lightly. Let them cool in the tins for a few minutes before turning them out onto a wire rack to cool completely.
- Make the chocolate icing: Place the broken pieces of plain chocolate into a heatproof bowl set over a pan of simmering water (a bain-marie). Make sure the bottom of the bowl does not touch the water. Heat gently, stirring occasionally, until the chocolate has melted. Add the butter and stir until it has completely melted into the chocolate.
- Assemble the cake: Once the cakes are cool, carefully slice each one in half horizontally to create four layers. Place the first layer on a serving plate or wire rack. Spoon some of the chocolate icing on top and spread it evenly. Place the next layer on top and repeat until all four layers are stacked.
- Ice the cake: Pour the remaining icing over the top of the cake, allowing it to drip down the sides. Use a palette knife to smooth the icing evenly over the top and sides. Leave the cake in a cool place (but not the fridge) to set.

Recipe Tips
- How to get a smooth icing? The key is to melt the chocolate and butter gently over low heat. Overheating the chocolate can cause it to lose its shine and become grainy.
- Can I make this cake ahead of time? Yes, the cake sponges can be baked a day in advance and stored in an airtight container. It’s best to ice the cake on the day you plan to serve it for the best finish.
- How to make the chocolate wave decorations? Melt the white and dark chocolate in separate bowls. Spread the chocolate onto strips of foil (about 4cm wide and 35cm long). Lay the strips carefully over mugs or tins placed on their sides to create a wavy shape, then place in the fridge to set before peeling off the foil.
- Why use the all-in-one method? Mary Berry’s method of mixing all the cake ingredients at once is incredibly simple and reduces the risk of the batter curdling, resulting in a consistently moist and tender cake.
What To Serve With Chocolate Birthday Cake
This rich and decadent cake is a celebration in itself, but it’s lovely with:
- A dollop of fresh, unsweetened whipped cream
- A scoop of high-quality vanilla bean ice cream
- A side of fresh raspberries or strawberries to cut through the richness
How To Store Chocolate Birthday Cake
- Room Temperature: Store the iced cake in a cool place in an airtight container for up to 3-4 days. Mary Berry advises against refrigerating the iced cake as it can dull the glossy finish of the chocolate.
Chocolate Birthday Cake Nutrition Facts
- Serving Size: 1 slice (1/12th of cake)
- Calories: 750 kcal
- Fat: 48g
- Carbohydrates: 72g
- Protein: 8g
Nutrition information is estimated and may vary based on ingredients and cooking methods used.
FAQs
Sunflower oil is recommended for its neutral flavor. You can substitute it with another neutral-flavored oil like vegetable or canola oil.
If the icing seems too thin, simply let it cool for a little longer. As the chocolate and butter cool, the icing will naturally thicken to a spreadable consistency.
Yes, but you will need to adjust the baking time. If you use larger tins, the layers will be thinner and bake faster. If you use smaller tins, they will be thicker and require a longer baking time.
Try More Recipes:
- Mary Berry All-in-One Chocolate Cake Recipe
- Mary Berry Chocolate Sponge Cake Recipe
- Mary Berry Raspberry and White Chocolate Scones Recipe

Mary Berry Chocolate Birthday Cake Recipe
Description
A truly indulgent and celebratory “Death by Chocolate” cake from Mary Berry, featuring four layers of moist chocolate sponge and a rich, glossy chocolate butter icing.
Ingredients
Instructions
- Preheat oven to 160°C/325°F. Grease and line two 20cm round cake tins.
- In a large bowl, mix all dry cake ingredients. Make a well in the center.
- Add all wet cake ingredients to the well and beat with a wooden spoon until a smooth batter forms.
- Divide the batter between the two tins and bake for 35 minutes until risen and springy. Cool completely.
- For the icing, gently melt the chocolate and butter together in a bowl over a pan of simmering water until smooth.
- Slice each cooled cake in half horizontally to make four layers.
- Stack the layers, spreading a portion of the icing between each one.
- Pour the remaining icing over the top and sides of the cake, smoothing with a palette knife. Let set in a cool place.
Notes
- This recipe uses a simple “all-in-one” method for the cake batter, making it very easy for beginners.
- Do not overheat the chocolate when making the icing, as this will cause it to lose its glossy shine.
- For the best result, allow the cake layers to cool completely before you begin to ice them.
- Store the finished cake at room temperature, not in the fridge, to maintain the icing’s shine.