James Martin Chocolate Cola Cake

Right, I’ll admit it: I rolled my eyes the first time I saw this recipe.

Cola, In a cake, I thought James Martin had finally gone off-piste — perhaps one too many Saturday mornings behind the hob. But I tried it (because curiosity always wins), and let me tell you… I was wrong. Very wrong.

This chocolate cola cake is outrageously rich, deeply moist, and carries the subtlest whisper of caramel from the cola that makes you think, “Wait, what is that?” — in the best possible way.

It’s a bit of a faff, I won’t lie. But it’s worth it. Just don’t be tempted to rush the frosting like I did the first time. Chocolate soup on sponge is not a look.

Ingredients List

For the Cake:

• 120g unsalted butter, softened — gives richness and softness
• 250ml cola — go for full-fat, dark cola (no diet nonsense here)
• 250g dark brown muscovado sugar — brings in depth and molasses tones
• 120g caster sugar
• 80g cocoa powder — use a good-quality one for proper flavour
• 4 large free-range eggs — binds and enriches
• 200ml buttermilk — makes the crumb tender and tangy
• 320g self-raising flour — ensures a fluffy rise
• 1 tsp bicarbonate of soda — reacts with the cola for extra lift

For the Chocolate Frosting:

• 400g Bournville chocolate, roughly chopped — sweet, smooth, and melts beautifully
• 100ml cola
• 100ml water
• 250g unsalted butter, diced
• 50g dark muscovado sugar
• Cocoa powder to dust (optional — I sometimes forget this and it’s fine)

How To Make It

1. Preheat your oven to 180°C (160°C fan/gas mark 4). Grease and line two 20cm cake tins.
2. Mix the cola and muscovado sugar in a jug until the sugar mostly dissolves. Set aside — it’ll look a bit swampy but trust the process.
3. Cream the butter and caster sugar with an electric mixer until light and fluffy (3-4 minutes).
4. Add the cocoa powder and beat again until you’ve got a rich, dark paste. It smells amazing at this point.
5. Whisk the eggs and buttermilk in a jug, then slowly add to the cocoa mixture while beating on low. It’ll look a bit curdled — that’s fine.
6. Sift in the flour and bicarb, mix gently, then pour in your cola-sugar swamp. Beat until smooth but don’t overdo it — think lazy Sunday stirring, not bootcamp.
7. Divide between tins and bake for 25–35 minutes. A skewer should come out clean. Cool in the tins for 5 minutes, then turn out onto a wire rack.
8. Now the frosting: Chuck your chopped chocolate into a heatproof bowl.
9. In a saucepan, heat the cola, water, butter, and muscovado sugar until the butter melts and it’s bubbling gently.
10. Pour it over the chocolate. Let it sit for a minute, then whisk until smooth and glossy.
11. Cover with cling film (touching the surface) and cool. Pop in the fridge for about an hour, giving it a stir now and then, until it’s spreadable.
12. Slice each sponge in half horizontally — you’ll have four layers. If your knife skills are rusty, just breathe and go slowly.
13. Stack and frost: cake, frosting, cake, frosting, repeat. Cover the top and sides with what’s left. Rustic swirls are charming — perfection is overrated.
14. Pop it in the fridge or a cool spot until ready to serve. Try not to keep opening the fridge just to stare at it. I do. It’s fine.

Common Mistakes

Why is my cake dry?
Overbaking or overmixing. Check at 25 minutes and stop mixing the second the batter is smooth.

Why did my frosting go runny?
You probably didn’t let it cool enough before using. I rushed it once — ended up with a chocolate slip ‘n slide.

Why is the cake dense?
Likely too much mixing or not enough lift. Make sure to sift the flour and don’t skip the bicarb.

Can I use Diet Coke?
No. Just… no. The sugar in regular cola is what caramelises and adds flavour. Diet versions don’t behave the same.

Storage And Reheating Tips

Fridge:
Wrap it well or pop it in an airtight container. Keeps for up to 5 days, though good luck having leftovers.

Freezer:
Freeze unfrosted layers wrapped in cling film. Frosting doesn’t freeze brilliantly — make that fresh.

To reheat a slice:
Microwave 15–20 seconds on medium, or oven-warm at 175°C, wrapped in foil, for about 10 minutes. Add cream. Be happy.

What To Serve With It

• Vanilla ice cream — the cold creaminess cuts through the richness.
• Fresh raspberries — that tart pop is perfect against the dark chocolate.
• Espresso or black coffee — not just for balance, but for sheer sophistication.

FAQ Section

Can I make this gluten-free?
Yes, swap the self-raising flour for a GF blend with xanthan gum. Add 1 tsp baking powder if needed.

Can I use milk chocolate instead of dark?
You can, but it’ll be sweeter and slightly less intense. I prefer the dark bite with the cola.

How far ahead can I make it?
You can bake and frost it a day in advance. Just keep it chilled and covered. The flavour actually improves overnight.

What cola brand is best?
Go classic — Coca-Cola or Pepsi. Store-brand cola lacks the caramel depth.

Try More Recipes:

• Plum Tarte Tatin James Martin
• James Martin Lemon Tiramisu