Brownie Mug Cake

Some days, I just need chocolate. Not a full cake. Not a dozen cookies. Just something warm, rich, and sweet that’s mine—all mine—and ready in minutes.

That’s how this brownie mug cake became my go-to. I didn’t plan it. I wasn’t trying to be clever. I just threw a few ingredients in a mug one night when I was too tired to bake and too stubborn to settle for store-bought.

One quick stir, one minute in the microwave, and I had something soft, gooey, and deeply chocolatey. I couldn’t believe how good it turned out.

Now I make it whenever I need a treat without making a mess. No mixer, no baking tray, no waiting. Just a spoon, a mug, and a little bit of joy.

If you’ve got cocoa powder, a bit of flour, and a microwave, you’re already halfway there. Add a scoop of ice cream on top, and honestly? It’s magic.

Table of Contents

Brownie Mug Cake Recipe

Ingredients (Serves 1):

4 tablespoons all-purpose flour (leveled)
4 tablespoons granulated sugar
2 tablespoons unsweetened cocoa powder
Pinch of salt (just a tiny pinch to balance flavor)
2 tablespoons neutral oil (like sunflower or canola)
3 tablespoons whole milk (room temperature)
1/4 teaspoon pure vanilla extract
1 tablespoon semisweet chocolate chips (plus more for topping)
1 small scoop of vanilla ice cream (for serving)

Instructions

Use a microwave-safe ceramic mug that holds at least 10–12 ounces to prevent overflow. A wide, straight-sided mug works best.
In the mug, whisk together flour, sugar, cocoa powder, and salt using a fork or small whisk until well combined and no lumps remain.
Pour in the oil, milk, and vanilla extract. Mix until everything is fully incorporated. Scrape the sides and bottom to make sure no dry patches are left.
Stir in 1 tablespoon of chocolate chips, gently folding them into the batter. These will melt into gooey pockets inside the brownie.
Microwave on high power for 1 minute and 10 seconds to 1 minute and 20 seconds, depending on your microwave’s wattage (usually around 1000W).
The top should look set but still soft and slightly gooey underneath when pressed. Do not overcook — it continues cooking as it rests.
Remove from microwave and let it sit for 1 minute. This helps the center firm up slightly while staying moist and fudgy.
Place a scoop of vanilla ice cream right on top of the warm brownie. Sprinkle with a few extra chocolate chips. Serve immediately with a spoon.
If you want a more molten center, reduce microwave time by 5 seconds. If you want a cake-like texture, microwave 10 seconds longer.
Serve on a napkin with a small spoon or gold dessert spoon for presentation — just like in the image. This dessert is best enjoyed warm and fresh.

How Do I Make a Brownie In a Mug Without Eggs?

You don’t need eggs to get a soft, fudgy texture in a mug brownie. Here’s how to make it work perfectly:

Use milk instead of eggs: 2–3 tablespoons of whole milk give the batter moisture without needing an egg.
Add oil or melted butter: 2 tablespoons of neutral oil or butter help keep the brownie soft and rich.
Don’t skip vanilla: Just 1/4 teaspoon of vanilla makes a big difference in flavor.
Avoid overmixing: Mix the batter just until combined – overmixing can make it dense.
Microwave the right amount of time: Too long in the microwave can dry it out fast, especially without eggs.

Why Is My Mug Brownie Dry Or Rubbery?

Dry or rubbery mug brownies are usually the result of a few small mistakes. Here’s how to fix it:

Overcooking: Even 10 extra seconds can dry out a brownie. Start with 1 minute and check.
Wrong mug size: A mug that’s too wide spreads the batter thin and dries it out.
Not enough liquid: Always use full-fat milk or add a little extra if the batter feels too thick.
Too much flour: Spoon and level the flour instead of scooping it straight from the container.
Microwave power too high: Some microwaves are stronger than others—reduce the time slightly if needed.

What Size Mug Should I Use For a Mug Brownie?

The size of the mug matters more than people think. Here’s what works best:

Use a mug that holds 10 to 12 oz (300–350 ml): This gives the batter room to rise without spilling.
Avoid narrow mugs: They cook unevenly and can overflow more easily.
Use a wide, microwave-safe mug: It helps heat spread evenly and keeps the top from drying out.

How Do I Make a Gooey Mug Brownie?

If you want that soft, melted-center bite, follow these tips:

Undercook slightly: Stop the microwave at around 1 minute if your wattage is high.
Use a spoon of chocolate chips or chunks: Fold them into the batter for gooey pockets.
Add a teaspoon of Nutella or chocolate spread: Place it in the center of the batter before microwaving.
Use oil instead of butter: It keeps the texture soft and moist.
Let it rest for 1 minute: This helps the middle finish cooking gently without drying out.

Is Mug Brownie Supposed To Rise In The Microwave?

Yes, it rises a little—just not like a cake.

Baking powder or soda causes lift: Even small amounts help give it height.
Rising is normal: It bubbles slightly as it cooks, creating a fluffy top and soft inside.
It settles as it cools: Don’t worry if it shrinks a little—it’s still soft and fudgy inside.

How Do I Stop My Mug Cake From Overflowing?

Overflow is common, but easy to avoid with a few small changes:

Use a large enough mug: Always go for 10–12 oz or more.
Don’t fill the mug more than halfway: Leave space for the batter to rise.
Stir properly: Unmixed baking powder or flour can cause uneven rising and spilling.
Use a microwave-safe plate under the mug: Just in case it rises too much, the cleanup is easier.

Why Does My Mug Brownie Taste Bitter?

A bitter taste usually means the cocoa or ratios are off. Here’s how to balance it:

Too much cocoa powder: Use 1.5 to 2 tablespoons—not more.
Not enough sugar: The sweetness should balance the cocoa. Add a full 4 tablespoons.
Low-quality cocoa: Use a natural unsweetened cocoa powder, not Dutch-processed.
Too much baking powder or soda: Use only a pinch or skip it if not needed.
Raw batter from undercooking: Always let it cook fully or rest after microwaving.