Amelia Grace Some days call for a proper baking project, and some days call for a cake that goes from cupboard to oven in ten minutes flat. This is very much the second kind.
The whole idea behind an all-in-one cake is exactly what it sounds like — every ingredient goes into one bowl together, and you simply beat it until smooth.
No separate creaming of butter and sugar, no careful folding in stages, none of the usual choreography of cake-making.
It sounds almost too easy to work, and yet this makes one of the richest, moistest chocolate cakes I know, largely thanks to a splash of hot water that loosens the batter and deepens the chocolate flavour.
Why the All-in-One Method Actually Works
It seems almost too simple to be reliable, but the science behind this method is sound.
Self-raising flour and baking powder together give the cake plenty of rise without needing air to be worked in through creaming, which is normally what butter and sugar being beaten together is for.
Using softened butter (not melted, and not fridge-cold) means it still combines smoothly with the other ingredients even without that separate creaming stage.
The hot water at the end is the real key to the finished texture — it loosens the batter to the right consistency and helps bloom the cocoa powder, making the chocolate flavour taste noticeably deeper and richer than a standard sponge.
Ingredients for Delia Smith All-in-One Chocolate Cake
- 200g self-raising flour
- 50g cocoa powder
- 1½ tsp baking powder
- 200g caster sugar
- 200g unsalted butter, softened
- 3 large eggs
- 2 tsp vanilla extract
- 4 tbsp hot water
For the Chocolate Icing:
- 150g dark chocolate, broken into pieces
- 100ml double cream
- 25g unsalted butter
How to Make Delia Smith All-in-One Chocolate Cake — Step by Step
Step 1 — Preheat and Prepare
Preheat your oven to 180°C (160°C fan / Gas 4). Grease and line a 20cm round cake tin.
Step 2 — Combine Everything
Put the flour, cocoa powder, baking powder, sugar, softened butter, eggs and vanilla extract all into one large mixing bowl.
Step 3 — Beat Until Smooth
Beat everything together with an electric whisk or wooden spoon for 2–3 minutes, until you have a smooth, evenly combined batter with no lumps of butter or flour visible.
Step 4 — Loosen with Hot Water
Add the hot water and beat briefly to combine. The batter should loosen to a soft, dropping consistency — it should fall easily off a spoon when you tap it gently.
Step 5 — Bake
Pour the batter into the prepared tin and spread evenly. Bake for 35–40 minutes, until well risen and a skewer inserted into the centre comes out clean.
Step 6 — Cool
Leave the cake in the tin for 10 minutes, then turn out onto a wire rack to cool completely before icing.
Step 7 — Make the Icing
Melt the dark chocolate, cream and butter together gently, either in short bursts in the microwave or in a heatproof bowl over a pan of simmering water, stirring until smooth and glossy.
Step 8 — Ice and Serve
Once the icing has cooled and thickened slightly, spread it generously over the top of the cooled cake, letting it drip down the sides a little.
My Top Tips for the Best Delia Smith All-in-One Chocolate Cake
Use softened butter, not melted. It needs to be soft enough to beat smoothly into the mixture, but still holding its structure — melted butter will make the cake noticeably greasy.
Don’t skip the hot water. It looks like an odd step, but it’s what gives this cake its deep, rich chocolate flavour and proper moist texture.
Beat until genuinely smooth before adding the water. Any lumps of butter that remain at this stage won’t disappear later, so take the extra minute to get it properly combined.
Let the icing cool and thicken slightly before spreading. Pouring it on too hot means it will simply run straight off the cake rather than sitting on top.
Test with a skewer a few minutes early. Ovens vary, and this cake can go from perfectly moist to slightly dry quite quickly, so start checking a few minutes before the time is up.
Serving Suggestions
This cake is rich enough to serve simply as it is, with the chocolate icing doing all the work. For something a little more special, add a scoop of vanilla ice cream alongside, or a spoonful of softly whipped cream. It also works beautifully as a base for a birthday cake, layered and filled with buttercream if you’d like to make it more of an occasion.
How to Store Delia Smith All-in-One Chocolate Cake
In the fridge: Not necessary for a day or two, but if your kitchen is particularly warm, store in an airtight container in the fridge for up to 5 days. Bring to room temperature before serving.
At room temperature: Store in an airtight container for up to 4 days.
In the freezer: Freeze the un-iced sponge, wrapped tightly in cling film and foil, for up to 3 months. Ice fresh once defrosted.
Delia Smith All-in-One Chocolate Cake Recipe
Ingredients
Method
- Preheat oven to 180°C (160°C fan / Gas 4). Grease and line a 20cm round tin.
- Combine flour, cocoa powder, baking powder, sugar, butter, eggs and vanilla in one bowl.
- Beat for 2–3 minutes until smooth.
- Add hot water and beat briefly to a soft, dropping consistency.
- Pour into the tin and bake for 35–40 minutes until a skewer comes out clean.
- Cool in the tin 10 minutes, then turn out onto a wire rack to cool completely.
- Melt chocolate, cream and butter together until smooth for the icing.
- Once slightly cooled and thickened, spread the icing over the cooled cake.
Notes
Frequently Asked Questions About Delia Smith All-in-One Chocolate Cake
Can I really put everything in one bowl at once?
Yes — that’s the entire idea behind this method. As long as your butter is properly softened (not melted or fridge-cold), everything combines together smoothly without needing separate creaming or folding stages.
Why does the recipe use hot water?
The hot water loosens the batter to the correct consistency and helps bring out the flavour of the cocoa powder, giving you a richer, more intense chocolate taste than you’d get without it.
Can I make this as a traybake instead?
Yes. Pour the batter into a greased and lined 30x20cm traybake tin and bake at the same temperature for 25–30 minutes. Ice directly in the tin and cut into squares.
Why did my cake sink in the middle?
This is usually down to slightly underbaking, or opening the oven door too early while the cake is still rising. Make sure the skewer comes out completely clean before removing it, and avoid opening the oven for at least the first 25 minutes.
