James Martin Chocolate Cola Cake

This chocolate cola cake is a deep, dark traybake with a soft, tender crumb and a glossy chocolate icing that sets like fudge. The cola doesn’t make it taste of fizzy drink, it simply boosts the cocoa flavour and keeps the sponge wonderfully moist. It’s an easy, one-bowl style bake that suits beginners, but still feels special enough for guests. Allow around 20 minutes prep, 25 minutes baking, plus cooling time, so about 1 hour 10 minutes in total.

Ingredients

For the cake

• 250ml cola (use it freshly opened)
• 125g unsalted butter
• 40g unsweetened cocoa powder
• 250g plain flour
• 300g light brown sugar
• 1 tsp bicarbonate of soda
• 1/2 tsp fine salt
• 2 large eggs
• 125ml buttermilk
• 1 tsp vanilla extract

For the chocolate icing

• 100ml cola
• 75g unsalted butter
• 25g unsweetened cocoa powder
• 250g icing sugar, sifted
• 100g dark chocolate (60–70%), finely chopped
• Pinch of fine salt

To finish (optional)

• 2 tbsp toasted pecans or hazelnuts, roughly chopped

How to Make This Chocolate Cola Cake

Oven and tin preparation

• Prepare the oven: Preheat the oven to 180°C or 160°C fan. Place a shelf in the middle of the oven so the cake bakes evenly.
• Line the tin: Grease a 23 x 33cm traybake tin, then line the base and sides with baking parchment, leaving a little overhang for easy lifting.

Mixing the batter

• Melt the cocoa mixture: Add 250ml cola, 125g butter and 40g cocoa powder to a saucepan. Warm gently, whisking, until the butter melts and the mixture looks smooth.
• Combine the dry ingredients: In a large bowl, whisk together the flour, brown sugar, bicarbonate of soda and salt. This breaks up any sugar lumps so the sponge stays even.
• Add eggs and buttermilk: Off the heat, whisk the eggs, buttermilk and vanilla into the warm cola mixture.
• Bring it all together: Pour the wet mixture into the dry ingredients and whisk until you have a smooth, glossy batter with no pockets of flour.

Baking

• Fill the tin: Pour the batter into the lined tin and level it gently with a spatula.
• Bake: Bake for 22–28 minutes. The cake is ready when it’s set and a skewer comes out with a few moist crumbs, but no wet batter.
• Don’t overbake: A minute too long can dry the crumb. Start checking at 22 minutes if your oven runs hot.

Cooling

• Cool briefly: Leave the cake in the tin for 10 minutes. This is the sweet spot for icing, warm enough to help it spread, but not so hot it turns runny.

Icing and assembling

• Make the icing base: In a saucepan, warm 100ml cola, 75g butter and 25g cocoa powder until melted and smooth.
• Whisk in the sugar: Take the pan off the heat and whisk in the sifted icing sugar until thick and glossy.
• Melt in the chocolate: Add the chopped dark chocolate and a pinch of salt, then stir until fully melted and shiny.
• Ice the cake: Pour the warm icing over the warm cake and spread right to the edges. Sprinkle with toasted nuts if using.
• Set before slicing: Leave at room temperature for 30–60 minutes, or until the top is set, then slice into squares.

Tips for Best Results

Why is my cake dry or crumbly?

The most common cause is overbaking. This sponge should be just set, not firm. Start checking early, and remember the cake continues to cook slightly as it cools in the tin.

How do I stop the icing going lumpy?

Sift the icing sugar and whisk it in off the heat. If you add sugar while the mixture is bubbling, it can form stubborn lumps. If you still get a few, a quick whisk with a balloon whisk usually smooths them out.

Can I make it without buttermilk?

Yes. Mix 125ml milk with 1 tablespoon lemon juice or white vinegar, leave for 5 minutes, then use in place of buttermilk. It gives the same gentle tang and helps keep the crumb soft.

How do I get neat slices with a clean top?

Let the icing set fully, then chill the cake for 20 minutes. Slice with a large knife dipped in hot water and wiped dry between cuts.

Serving Suggestions

• Serve slightly warm with vanilla ice cream.
• Pair with softly whipped cream and fresh raspberries.
• Enjoy with a strong coffee or a mug of tea for an easy afternoon treat.
• Add a pinch of flaky sea salt over the icing for a grown-up finish.

Storage

Room temperature

Keep the cake in an airtight container for up to 2 days. If your kitchen is warm, store it somewhere cool and out of sunlight so the icing stays firm.

Refrigerator

Store in an airtight container for up to 5 days. Bring slices to room temperature for 20–30 minutes before serving so the sponge softens and the flavour comes through.

Freezing

Freeze sliced portions for up to 2 months. Wrap each slice in baking parchment, then seal in a freezer bag or container. Defrost at room temperature for 2–3 hours, or overnight in the fridge.

Nutrition

• Calories: 480 kcal
• Carbohydrates: 72 g
• Protein: 5 g
• Fat: 20 g
• Saturated fat: 12 g
• Sodium: 280 mg

Nutrition values are estimates and will vary depending on the ingredients and brands you use.

FAQs

If you love chocolate cakes that stay soft for days, this one earns a permanent place in your baking rota. It’s simple, reliable, and the shiny icing makes it look far more impressive than the effort involved.

Chocolate Cola Cake

Recipe by Milli Rose

0.0 from 0 votes

Course: DessertCuisine: BritishDifficulty: Easy

Servings

12

slices

Prep time

20

minutes

Cooking time

25

minutes

Total time

70

minutes

Calories

480

kcal

45

minutes

Rich, moist chocolate cola traybake with a glossy fudge-style chocolate icing. Easy to make, slices beautifully, and stays soft for days.

Ingredients

• For the cake

• 250ml cola (not flat)

• 125g unsalted butter

• 40g unsweetened cocoa powder

• 250g plain flour

• 300g light brown sugar

• 1 tsp bicarbonate of soda

• 1/2 tsp fine salt

• 2 large eggs

• 125ml buttermilk (or see FAQ for substitute)

• 1 tsp vanilla extract

• For the chocolate icing

• 100ml cola

• 75g unsalted butter

• 25g unsweetened cocoa powder

• 250g icing sugar, sifted

• 100g dark chocolate (60–70%), finely chopped

• Pinch of fine salt

• To finish (optional)

• 2 tbsp toasted pecans or hazelnuts, roughly chopped

Directions

• Preheat the oven to 180°C (160°C fan). Grease and line a 23 x 33cm traybake tin with baking parchment.
• In a saucepan, heat the cola, butter and cocoa gently until the butter melts. Whisk smooth and take off the heat.
• In a large bowl, whisk together the flour, brown sugar, bicarbonate of soda and salt to remove any lumps.
• Whisk the eggs, buttermilk and vanilla into the warm cola mixture, then pour into the dry ingredients and whisk until smooth.
• Pour into the tin and bake for 22–28 minutes, until a skewer comes out with a few moist crumbs but no wet batter.
• Cool in the tin for 10 minutes while you make the icing.
• For the icing, heat the cola, butter and cocoa until melted. Off the heat, whisk in the icing sugar, then add the chopped dark chocolate and salt. Stir until glossy.
• Pour the warm icing over the warm cake, spread to the edges, and leave to set for 30–60 minutes before slicing.

Notes

• Sifting the icing sugar keeps the topping silky and prevents little white lumps.
• Don’t overbake the sponge. It should be set, but still soft in the centre.
• For neat slices, chill the cake for 20 minutes once the icing is set, then cut with a hot, dry knife.