Hot Chocolate Mug Cake (Made with Hot Cocoa Mix)
This hot chocolate mug cake starts with a packet of hot cocoa mix — the same one you would stir into a mug of milk — and turns it into a warm, fudgy cake in about two minutes. The mix brings cocoa, sugar and milk powder in one go, so you only need flour, a little sugar, baking powder, melted butter and hot water. It is the easiest mug cake on the site and a great way to use up the last packet in the box. Prefer to bake from scratch with cocoa powder? Our hot cocoa mug cake uses no mix at all.
Why you'll love this
- Made with a cocoa packet. No measuring cocoa or milk powder.
- Ready in 2 minutes. Mix and microwave in one mug.
- Fudgy centre. Slightly underbaked for a molten middle.
- Tastes like hot chocolate. The mix gives a creamy, milky chocolate flavour.
- Pantry-friendly. Flour, butter, sugar and a cocoa packet.
- Fun to top. Marshmallows, whipped cream or ice cream.
Key ingredients & how to use them
- Hot cocoa mix — one standard packet, about 1 ounce (28 g). It provides the cocoa, sweetness and milk solids. Richer, darker mixes give a deeper chocolate flavour.
- All-purpose flour — a quarter cup, spooned and levelled, for structure.
- Sugar — two teaspoons. Adjust to taste, as cocoa mixes vary in sweetness.
- Baking powder — a quarter teaspoon for a light, cakey rise.
- Melted butter — two tablespoons for richness and a moist crumb.
- Hot water — two tablespoons. Hot water dissolves the cocoa mix smoothly, just like when you make a drink.
- Chocolate chips or nuts — optional extras for texture.
How to make it (step by step)
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1
Combine the dry ingredients
In a large microwave-safe mug, stir together the hot cocoa mix, flour, sugar and baking powder with a fork until evenly combined.
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2
Add the butter and hot water
Pour in the melted butter and hot water and mix until you have a smooth, glossy batter with no dry spots. Scrape the bottom of the mug so no mix is left behind.
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3
Add extras
Stir in a spoonful of chocolate chips or chopped nuts if you like.
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4
Microwave
Cook on high for 60 to 90 seconds, until the edges are set and the centre is still slightly moist. A slightly gooey centre gives you the fudgiest result.
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5
Rest and serve
Let it cool for a minute. Top with whipped cream, mini marshmallows or a scoop of ice cream and eat straight from the mug.
Troubleshooting
- It is dry. It was overcooked. Stop when the centre still looks slightly moist.
- It is too sweet. Skip the extra sugar; some cocoa mixes are very sweet.
- Lumpy batter. Use hot water and stir well so the mix dissolves.
- It overflowed. Use a mug that holds at least 10 oz.
- It is rubbery. Microwave in shorter bursts.
- Weak chocolate flavour. Use a dark or rich cocoa mix, or add a teaspoon of cocoa powder.
Hot chocolate mug cake vs hot cocoa mug cake
The names sound interchangeable, and on this site they are two different recipes. This hot chocolate mug cake is built around a packet of instant hot cocoa mix, which already contains cocoa, sugar and milk powder. It is the quickest version and tastes like a mug of creamy hot chocolate in cake form.
Our hot cocoa mug cake is made from scratch with unsweetened cocoa powder, sugar, milk and oil. It has a darker, more classic chocolate-cake flavour and you can control the sweetness exactly. Make this one when you have cocoa packets to use up, and that one when you have cocoa powder in the cupboard.
Pro tips
- Use a big mug — the batter rises a lot.
- Choose a rich or dark hot chocolate mix for the best flavour.
- Take it out while the centre is still a little moist.
- Add a pinch of salt to balance the sweetness.
- Drop a square of chocolate into the centre for a molten middle.
- Let it rest for a minute before eating.
Variations
- S’mores. Top with marshmallows and crushed graham crackers.
- Peppermint. Use a peppermint hot cocoa mix or add a drop of extract.
- Salted caramel. Drizzle with caramel sauce and flaky salt.
- Mocha. Use hot coffee instead of hot water.
- Molten centre. Push a square of chocolate into the batter before cooking.
- Nutty. Fold in chopped hazelnuts or walnuts.
Storage
This mug cake is best eaten warm, right away. If needed, cover and refrigerate for up to a day and warm it for 10 to 15 seconds. Keep a few cocoa packets and small bags of the other dry ingredients ready for instant mug cakes.
Serving ideas
Top with whipped cream and mini marshmallows for a hot-chocolate feel, or a scoop of vanilla ice cream. For more chocolate mug cakes, try our Oreo mug cake and Biscoff mug cake.
More recipes to try
One mug and a spoon is my kind of dessert. The hot cocoa mug cake is the closest cousin to this one, so start there if the cocoa-forward flavor is what you liked. Days when I want something more nutritious alongside the chocolate, I make the Shakeology mug cake, and when the pantry is nearly bare, the pancake mix mug cake saves me.
Recipe
Hot Chocolate Mug Cake
A fudgy single-serving hot chocolate mug cake made with a packet of hot cocoa mix, flour, sugar, baking powder, melted butter and hot water, cooked in the microwave in about 2 minutes.
Ingredients
- 1 packet hot cocoa mix
- 1/4 cup all-purpose flour
- 2 teaspoons granulated sugar (adjust to taste)
- 1/4 teaspoon baking powder
- 2 tablespoons unsalted butter, melted
- 2 tablespoons hot water
- Optional: chocolate chips or chopped nuts
Instructions
- In a microwave-safe mug, combine the hot cocoa mix, flour, sugar and baking powder.
- Add the melted butter and hot water and mix until smooth with no dry spots.
- Stir in chocolate chips or nuts if using.
- Microwave on high for 60 to 90 seconds until the edges are set but the centre is still slightly moist.
- Let cool for 1 minute and serve, topped with whipped cream or ice cream if desired.
Tips & notes
- Use a standard 1 oz (28 g) packet of hot cocoa mix.
- Reduce or skip the sugar if your cocoa mix is very sweet.
- Use a mug that holds at least 10 oz.
Nutrition · per serving (estimate)
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Frequently asked questions
Can I use any hot cocoa mix?
Yes. Any standard 1 oz packet works. Dark or rich chocolate mixes give the deepest flavour; sugar-free mixes work too but the cake will be less sweet.
What is the difference between this and the hot cocoa mug cake?
This recipe uses a packet of instant hot cocoa mix. The hot cocoa mug cake is made from scratch with unsweetened cocoa powder, sugar, milk and oil.
Can I use milk instead of hot water?
Yes, warm milk makes it richer. Most cocoa mixes already contain milk powder, so hot water works perfectly.
Why is my mug cake dry?
It was cooked too long. Stop when the edges are set but the centre still looks slightly moist.
Can I make it without butter?
Use 2 tablespoons of neutral oil instead; the cake will be slightly less rich but just as moist.
Can I add marshmallows?
Yes. Add mini marshmallows on top for the last 10 seconds of cooking, or right after it comes out.
How big should the mug be?
At least 10 oz, so the batter can rise without spilling.
Can I make it ahead?
It is best fresh. You can pre-mix the dry ingredients with the cocoa packet in a jar for a quick mug cake later.
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