Hot Chocolate Mug Cake Recipe (2-Min Microwave) – Easy & Cozy
Cocoa powder, a touch of milk chocolate, and mini marshmallows — the flavor of a cup of hot chocolate — turn into a warm, fluffy microwave cake in one mug here. It bakes up soft rather than dense, closer to a cake than a brownie, and the marshmallows melt into gooey pockets as it cooks. It’s ready faster than the microwave takes to heat up an actual mug of cocoa.
Ingredients
- 4 tbsp all-purpose flour
- 3 tbsp granulated sugar
- 1 tbsp unsweetened cocoa powder
- 1/4 tsp baking powder
- Pinch of salt
- 3 tbsp milk
- 2 tbsp neutral oil
- 1/4 tsp vanilla extract
- 2 tbsp mini milk chocolate chips
- 1/4 cup mini marshmallows, divided
Instructions
- In a large microwave-safe mug, whisk together the flour, sugar, cocoa powder, baking powder, and salt.
- Add the milk, oil, and vanilla extract, and stir until smooth.
- Fold in the chocolate chips and half the mini marshmallows.
- Microwave on high for 70 to 90 seconds, until the cake has risen and looks mostly set on top, with maybe a small soft spot in the center.
- Immediately press the remaining marshmallows into the hot top of the hot chocolate mug cake so they start to melt and turn gooey.
- Let it sit for 1 to 2 minutes before eating, since the mug and cake are very hot straight out of the microwave.
Why This Hot Chocolate Mug Cake Works
Using more flour relative to fat than a brownie-style mug dessert gives this hot chocolate mug cake a lighter, more cake-like crumb instead of a dense, fudgy one. Adding the marshmallows in two stages — a few baked in, a few pressed on right after — means some melt into the cake for gooeyness while the ones on top stay visible and pillowy instead of disappearing completely.
Tips for the Best Hot Chocolate Mug Cake
Use a mug that holds at least 12 ounces, since this hot chocolate mug cake rises significantly in the microwave and can overflow a smaller one. Stop the microwave as soon as the cake looks mostly set — a slightly soft center firms up as it rests, while an overcooked one turns rubbery fast. Press the finishing marshmallows on right when it comes out of the microwave; the residual heat is what melts them without needing extra cook time.
Common Mistakes to Avoid
Using a mug that’s too small is a common mistake, since the batter can rise over the rim and make a mess in the microwave. Overcooking by even 20 to 30 seconds turns the texture rubbery and dry instead of soft. Adding all the marshmallows before microwaving instead of saving some for the top means you lose the pillowy, half-melted marshmallow layer that makes this taste like an actual cup of cocoa.
What to Serve With a Hot Chocolate Mug Cake
A drizzle of extra chocolate syrup or a dusting of cocoa powder on top makes it feel more finished. Pair it with a real mug of coffee or tea on the side for a cozy after-dinner treat.
Storage
This hot chocolate mug cake is best eaten immediately, since the light, fluffy texture and gooey marshmallows don’t hold up once it cools — it turns dense and the marshmallows harden. If you want to prep ahead, measure the dry ingredients into the mug and store it covered, then stir in the wet ingredients right before microwaving.
Frequently Asked Questions
Can I make this hot chocolate mug cake without marshmallows? Yes — it still tastes like a rich chocolate mug cake without them, just without the melted marshmallow layer on top.
Why did my hot chocolate mug cake overflow in the microwave? The mug was likely too small — use one that holds at least 12 ounces so the batter has room to rise as it cooks.
Can I use hot cocoa mix instead of cocoa powder? Yes, though you should reduce the added sugar slightly since hot cocoa mix is already sweetened, and taste the batter before microwaving.
Can I add mini chocolate chips inside the batter as well as on top? Yes — folding in a few extra chocolate chips before microwaving adds more melted pockets throughout the cake.
