Chocolate Mug Cake with Cocoa Powder (90 Seconds, One Mug)
A mug cake is the fastest way to find out whether your cocoa powder is any good. There is no chocolate bar, no frosting and no time — the cocoa is doing all of the work, in about five minutes.
Most mug cakes come out rubbery. That is almost always overcooking, not a bad recipe.
How do you make it?
Makes: 1 mug cake · Prep: 3m · Total: 5m
Ingredients
- 4 tbsp (30 g) all-purpose flour
- 2 tbsp (10 g) unsweetened cocoa powder
- 3 tbsp (36 g) granulated sugar
- ¼ tsp baking powder
- Pinch of salt
- 3 tbsp (45 ml) milk
- 2 tbsp (28 g) melted butter or neutral oil
- ¼ tsp vanilla extract
- 1 tbsp chocolate chips (optional)
Method
- Mix dry. In a wide 12 oz mug, whisk the flour, cocoa, sugar, baking powder and salt with a fork until the colour is completely even. Dry pockets of cocoa are what make mug cakes taste bitter in patches.
- Add wet. Pour in the milk, melted butter and vanilla. Stir just until no dry flour remains — about 20 seconds. Stop there.
- Rest 1 minute. Let the batter sit for a minute before it goes in. This hydrates the flour and is the difference between spongy and rubbery.
- Microwave. Cook on high for 70–90 seconds. Stop while the very centre still looks slightly wet; it sets from residual heat within a minute.
- Serve. Eat straight from the mug while warm. It firms up fast, so it does not keep.
Why do mug cakes turn out rubbery?
Two reasons, and both are easy to fix.
Overcooking. A microwave keeps cooking the cake after it stops. At 90 seconds the centre should still look underdone. If it looks perfect in the microwave, it will be dry on the spoon.
Overmixing. Beating the batter develops gluten, and gluten in a 90-second cake means chew. Stir until the flour disappears, then put the fork down.
What kind of cocoa powder should you use?
Unsweetened natural (non-alkalized) cocoa. It reacts with the baking powder and gives a lighter crumb, and its natural acidity keeps a very sweet batter from tasting flat.
Dutch-processed cocoa makes a darker, milder cake and rises slightly less in this recipe. Neither is wrong — see non-alkalized vs Dutch-processed cocoa for what changes.
Can you make it without eggs?
This recipe already has none. Eggs in a mug cake are what make it turn omelette-like, so leaving them out is deliberate rather than a compromise.
Can you make it dairy-free or gluten-free?
Yes to both. Oat milk and neutral oil work with no other change. For gluten-free, a 1:1 baking blend works, but rest the batter for two minutes instead of one.
How do you make it less sweet?
Drop the sugar to 2 tbsp and add an extra teaspoon of cocoa. It becomes closer to a warm brownie than a cake. Since the cocoa is unsweetened, you control this completely — which is the main reason to keep unsweetened cocoa in the cupboard rather than a drinking-chocolate mix.
The cocoa matters more than anything else here. Ours is single-origin Vietnamese Trinitario — unsweetened, non-alkalized, with heavy-metal and flavanol reports published in full on our Lab Results & Awards page. Shop on Amazon →
Common questions
Why is my mug cake rubbery?
Almost always overcooking. Microwaves keep cooking after they stop, so pull the cake while the centre still looks slightly wet. Overmixing the batter is the second cause.
Can I make a mug cake without eggs?
Yes. This recipe uses no eggs at all. Eggs are what give many mug cakes a rubbery, omelette-like texture.
What cocoa powder is best for mug cake?
Unsweetened natural non-alkalized cocoa. It reacts with baking powder for a lighter crumb and its acidity balances the sugar.
How long do you microwave a mug cake?
70 to 90 seconds on high in a 12 oz mug. Start checking at 70 seconds.
Where to go next
These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.