There's something instant and satisfying about whipping up a brownie in just minutes, and this Fudgy Mug Brownie Recipe nails that indulgence with minimal fuss. It’s rich, chocolaty, and so delightfully fudgy — enough to brighten even the busiest day.

A white cup filled with a dark chocolate dessert that has a rough, moist texture. Large glossy melted chocolate chunks are scattered on the top layer, melting slightly into the dark base. The cup is placed on a white marbled surface with chocolate pieces in the background, and a silver spoon lies next to it. photo taken with an iphone --ar 2:3 --v 7

Jump to:

Why You'll Love This Recipe
Ingredients & Why They Work
Make It Your Way
Step-by-Step: How I Make Fudgy Mug Brownie Recipe
Top Tip
How to Serve Fudgy Mug Brownie Recipe
Make Ahead and Storage
Frequently Asked Questions:
Final Thoughts
Fudgy Mug Brownie Recipe

Why You'll Love This Recipe

I’m a huge fan of desserts that don’t require an arsenal of ingredients or tons of time but still feel utterly indulgent. This fudgy mug brownie became my go-to for solo sweet cravings since it’s quick to make and delightfully rich—like having a tiny chocolate hug right in your mug.

Speedy Satisfaction: You get a warm, freshly baked brownie in under five minutes, no oven involved.
Minimal Ingredients: Just a few pantry staples come together to create a decadent dessert.
Perfect Portion: This mug-sized treat is just right without tempting you to go overboard.
Fun and Foolproof: It’s almost impossible to mess up, so you’ll feel confident making it anytime.

Ingredients & Why They Work

This Fudgy Mug Brownie Recipe brings together simple ingredients that create a beautifully rich, moist, and fudgy texture without the need for eggs or butter. Each component plays a key role — and I’ll share tips so you know what to look for on your next grocery trip.

Flat lay of a small mound of rich dark brown dutch process cocoa powder, a small pile of fine pale all purpose flour, a small heap of white granulated sugar, a small white ceramic bowl filled with golden vegetable oil, a small white ceramic bowl with clear water, a few pieces of chopped glossy dark chocolate, all arranged in perfect symmetry on a clean white marble surface, soft natural light, photo taken with an iPhone, professional food photography style, fresh ingredients, white ceramic bowls, no bottles, no duplicates, no utensils, no packaging --ar 2:3 --v 7 --p m7354615311229779997

Dutch Process Cocoa Powder: This cocoa offers a smoother, richer chocolate flavor with less acidity, which makes the brownie deeply fudgy.
All-Purpose Flour: Just a bit to give the brownie structure without making it cakey.
Granulated Sugar: Sweetens and balances the cocoa’s bitterness perfectly.
Oil (Canola, Vegetable, or Olive): Keeps the brownie moist and tender — olive oil adds a little fruity depth, but canola or vegetable are neutral options.
Water: Hydrates the dry ingredients and helps form that smooth batter texture.
Chopped Dark Chocolate: Adding chocolate chunks creates molten pockets of ooey-gooey happiness in every bite.

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Note: You'll find the complete list of ingredients, along with their exact measurements, in the printable recipe card at the bottom of this post.

Make It Your Way

One of the best things about this Fudgy Mug Brownie Recipe is how customizable it is. I like to switch things up based on what kind of chocolate I have or to add a quick punch of extra flavor — and you absolutely should, too!

Chocolate Variety: I sometimes swap dark chocolate for milk chocolate or white chocolate chunks for a sweeter twist. Each brings a different flavor and melt texture that’s fun to experiment with.
Add-Ins: For a nutty crunch, I toss in chopped walnuts or pecans before microwaving — it’s a simple way to amp up texture and flavor.
Dietary Swap: I’ve used coconut oil instead of vegetable oil for a subtle coconut aroma, especially if you enjoy a tropical note.
Egg Substitute: If you want a slightly denser brownie crumb (since this recipe skips the egg), you can whisk in a tablespoon of beaten egg in place of some of the water. It’s a neat trick if you prefer a bit more binding.

Step-by-Step: How I Make Fudgy Mug Brownie Recipe

The image shows a close-up of a white round ramekin filled with a dark chocolate dessert that has a rough and crumbly texture. On the top layer, melted glossy chocolate patches spread unevenly across the surface, giving a shiny contrast to the dark cake-like base. A spoon lifting a portion from the ramekin reveals the moist inside mixed with melted chocolate, creating a rich and textured look. The background is a white marbled surface, and a woman's hand is gently holding the spoon. photo taken with an iphone --ar 2:3 --v 7

Step 1: Mix the dry ingredients in your favorite mug

I love starting with an 8 oz microwave-safe mug and adding the cocoa powder, flour, and sugar first. Grab a mini whisk or small fork and whisk these together well — this helps break up any lumps so your brownie batter is smooth at the start.

Step 2: Add wet ingredients and combine

Pour in your chosen oil and water. Whisk briskly but carefully — you want a shiny, lump-free batter. Don’t worry if it feels a little thick, it’s supposed to be that way for a fudgy texture.

Step 3: Stir in half the chocolate chunks, save some for the top

Drop half of your chopped chocolate into the batter and gently stir it through. This spreads the melty chocolate bits inside your brownie. Then sprinkle the remaining chocolate chunks on top to create a glossy chocolatey surface after microwaving.

Step 4: Microwave and then cool just a bit

Place your mug in the microwave and cook on full power for about 40 seconds. (If your microwave is stronger or weaker, you might need to adjust this — I use 1000 watts, so slower microwaves may need 50 seconds.) Look for a brownie top that’s no longer wet but still a touch moist. Let it sit and cool for a few minutes so that fudgy texture sets beautifully.

Top Tip

Making this mug brownie is pretty foolproof, but from my experience, these tips really help you get perfect results every time.

Right Mug Size: Use an 8 oz mug to prevent overflow and ensure the brownie cooks evenly.
Microwave Wattage Adjustment: I learned the hard way to tweak cooking times based on your microwave’s power—start low and add a few seconds if needed.
Don’t Overcook: The brownie continues to cook a little after microwaving, so pulling it out while it’s still slightly moist gives the best fudgy texture.
Spoon It Right: Since it won’t slice out like a traditional brownie, grab a spoon — eating it straight from the mug is part of the cozy charm!

How to Serve Fudgy Mug Brownie Recipe

Garnishes

Keep it simple or fancy — I often top my mug brownie with a spoonful of vanilla ice cream or a dollop of whipped cream. A sprinkle of flaky sea salt or a drizzle of caramel sauce brings it to another level, but really, it’s amazing on its own.

Side Dishes

For a little contrast, fresh raspberries or sliced strawberries are my go-to. A cup of coffee or a rich hot chocolate alongside the mug brownie creates a comforting mini-dessert experience.

Creative Ways to Present

I’ve brought this recipe to casual get-togethers by setting out a “DIY mug brownie bar” with toppings like nuts, mini marshmallows, and fruit preserves—such a hit! Try layering the batter in a clear glass mug with alternating chocolate chunks and maybe even a sprinkle of chili powder for a surprising depth of flavor.

Make Ahead and Storage

Storing Leftovers

Because this brownie is best eaten fresh and warm, leftovers don’t keep their charm as well. But if you do want to save some, cover the mug tightly with plastic wrap and store it in the fridge for up to 2 days. It won’t be as fudgy but still tasty reheated.

Freezing

I don’t usually freeze this mug brownie because of its soft texture, but if you want to try, wrap it snugly and freeze in a small airtight container. Thaw in the fridge overnight and reheat gently.

Reheating

Pop the mug back in the microwave for about 15 seconds to warm it up. Be careful not to overheat, or it dries out. That short burst refreshes the gooey texture nicely.

Frequently Asked Questions:

Can I use regular cocoa powder instead of Dutch process?

You can substitute regular cocoa powder, but the flavor might be a bit more acidic and less smooth. Dutch process cocoa gives a richer chocolate taste that really makes this fudgy mug brownie stand out.

My brownie turned out dry. How can I fix this?

Dry brownies usually mean it was overcooked. Try decreasing microwaving time by 5-10 seconds and remember to remove it when the top is just set but still a little moist. Using oil and water instead of butter also helps keep it moist if you follow the recipe exactly.

Can I double the recipe for a bigger mug brownie?

While it’s tempting to make a big brownie, I recommend making two separate mug brownies instead. They cook more evenly this way, and you avoid a soggy or undercooked center that can happen with doubling the batter.

Why doesn’t this recipe use eggs?

I skipped eggs to keep the recipe super simple and quick. Without eggs, the texture is a bit looser and more crumbly but still wonderfully fudgy. If you want firmer brownies, you can replace one tablespoon of water with a whisked egg.

Final Thoughts

This Fudgy Mug Brownie Recipe has saved me on more than one occasion when I wanted a sweet treat fast without turning on the oven or dirtying multiple dishes. It’s cozy, rich, and perfectly portioned for one — a tiny warm celebration you can make anytime. I hope you love it as much as I do and find yourself reaching for it whenever a chocolate craving strikes.