Chocolate Chip Mug Cake

Some nights, I just want something sweet that doesn’t ask for much—no oven, no mixers, no waiting.

Just a few minutes, one mug, and the kind of dessert that makes you pause after the first bite because yes, it really is that good.

This chocolate chip mug cake is my go-to when I need something warm and chocolatey right now.

It’s soft and cake-y around the edges, a little gooey in the center, and packed with melty chocolate chips that stay creamy even after microwaving.

Honestly, it tastes like a warm cookie and a soft cake had a baby—and it was raised in a coffee mug.

The best part? It takes less than five minutes from start to finish, and you don’t even have to dirty more than a spoon and a mug. No fancy steps, no hard-to-pronounce ingredients, and no chance of messing it up.

I’ve made it on lazy nights, after long days, and even once in the middle of the afternoon just because I wanted something cozy with my tea.

If you’ve got a microwave, a mug, and a handful of basic ingredients, you’re already halfway there.

Table of Contents

Chocolate Chip Mug Cake Recipe

Ingredients (for 1 mug cake):

2 tablespoons unsalted butter
2 tablespoons light brown sugar (packed)
1 tablespoon white granulated sugar
1/4 teaspoon pure vanilla extract
Pinch of salt (just under 1/8 teaspoon)
1 egg yolk (room temperature – not the whole egg)
3 tablespoons all-purpose flour (leveled)
2 tablespoons semi-sweet chocolate chips (plus a few extra for topping)

Instructions

Use a microwave-safe ceramic mug that holds at least 8 oz (240 ml). Avoid tall or narrow mugs to ensure even cooking.
Place the butter in the mug and microwave for about 25–30 seconds or until completely melted but not bubbling.
Stir in the light brown sugar and white sugar directly into the melted butter using a fork or mini whisk. Mix until fully combined and smooth. Add vanilla extract and a small pinch of salt. Stir again.
Separate one egg and discard or save the egg white. Add only the yolk into the mug. Whisk it in until the mixture becomes glossy and emulsified.
Gently stir in the all-purpose flour. Do not overmix—just enough until no dry flour remains. Scrape the sides and bottom well.
Mix in 2 tablespoons of semi-sweet chocolate chips. Press them slightly down so they’re spread throughout. Reserve 5–6 chips and gently press them on the top to give that melty, bakery-style finish.
Microwave on medium power (about 600–700W if adjustable) for 45–55 seconds. The cake should puff up, look set on top, and feel firm to the touch with a slightly gooey center.
If your microwave only has high power (1000W or above), reduce cooking time to 35–40 seconds and check doneness.
Let the mug cake sit for 1–2 minutes before digging in. This helps finish cooking the middle gently and allows the chocolate chips to melt perfectly.
Top: Slight crisp edge with fully melted chocolate chips.
Center: Moist, buttery, slightly gooey with soft pockets of chocolate.
Bottom: Light and fluffy with a slight chew, like a baked cookie meets cake.

How Do I Make a Chocolate Chip Mug Cake Without Eggs?

Yes, you can still make a soft and tasty mug cake without using eggs. Just follow these tips:

Use milk for moisture: Replace the egg with 2 tablespoons of milk to keep the batter smooth.
Add a bit of fat: Use a little extra butter or oil (about ½ tablespoon more) to make up for the richness an egg gives.
Mix just enough: Stir until combined – don’t overmix or the cake may turn dense.
Microwave time may change: Cakes without eggs may cook slightly faster, so check around 40 seconds.

Can I Make a Chocolate Chip Mug Cake Without Baking Powder?

You can skip baking powder and still get a decent rise with the right changes. Here’s how:

Use self-raising flour instead: It already contains baking powder.
Try baking soda with acid: Mix 1/8 teaspoon baking soda with 1/4 teaspoon vinegar or lemon juice.
Whipped egg yolk trick: Whipping the yolk lightly with a fork adds a little lift.
Don’t expect a big rise: The texture will be slightly denser without a full leavening agent.

Why Is My Mug Cake Rubbery Or Dry?

If your mug cake turns out too chewy or dry, these are the likely reasons:

Overcooking: Microwaving for too long dries it out fast. Always start with 45 seconds.
Too much flour: Extra flour makes the cake heavy and tough. Measure using the spoon-and-level method.
No fat or egg: Skipping butter or yolk can lead to rubbery texture.
Incorrect mug size: A very tall or narrow mug can cause uneven cooking. Use a wide one instead.

How Do I Keep a Mug Cake Soft And Moist?

A few simple changes can make a big difference in texture:

Use butter or oil: Fats help trap moisture and make the cake tender.
Add an egg yolk or milk: Both help make the cake soft without drying it out.
Microwave in short bursts: If the cake is undercooked, add 5–10 seconds at a time.
Don’t overmix: Mix just until the flour disappears.
Use the right mug: A wider mug allows more even cooking.

Are Mug Cakes Safe To Eat If They’Re Gooey In The Center?

Yes – as long as the ingredients used are safe to eat with a soft center. Here’s what to keep in mind:

No raw flour taste: The flour should be fully cooked even if the center is gooey.
Use pasteurized eggs: If using egg yolk, it should be cooked through or safe.
Stick to short resting time: Let it sit for 1–2 minutes after microwaving to finish cooking gently.
Check temperature: The mug should feel hot to the touch, especially at the bottom.

What’s The Best Way To Stop Chocolate Chips From Sinking In a Mug Cake?

You want your chocolate chips spread evenly – not all stuck at the bottom. Here’s how to help them float:

Coat in flour: Toss chocolate chips in a tiny bit of flour before adding them.
Use mini chips: They’re lighter and more likely to stay in place.
Fold them in last: Stir them in after the batter is fully mixed.
Save a few for topping: Press some chips gently on top before microwaving.

Can I Double The Recipe To Make Two Servings?

Yes – but don’t just double everything without adjusting a bit. Here’s how to do it right:

Use two separate mugs: Doubling in one mug may cook unevenly.
Double ingredients carefully: Measure each one twice instead of multiplying in your head.
Microwave each separately: Cook one at a time for best results.
Adjust cook time: Second mug might cook faster if microwave is already warm.

Is It Okay To Refrigerate Leftover Mug Cake?

Yes, if you don’t finish it, you can store it safely. Here’s how:

Cool it completely first: Never store while it’s still warm.
Cover the mug or transfer to container: To keep it from drying out.
Eat within 1–2 days: Reheat for 10–15 seconds before eating.
Don’t freeze: Mug cakes get dense and rubbery after freezing.