This keto brownie in a mug is super fudgy, chocolatey, egg free and gluten-free. Best of all, it cooks in the microwave in just 60 seconds.
Aren't mug cakes just the most brilliant invention? I think the ability to produce a healthy single serve cake in 3 minutes from start to finish is nothing short of a miracle.
I have a whole bunch of keto mug cakes on my website already. We love the chocolate mug cake, this peanut butter mug cake, my vanilla keto mug cake and also the coconut flour mug cake.
I have even made a mug cheesecake. As you can see, I am taking mug cakes seriously.
But I have to say, this one is special. It is so fudgy, satisfies the strongest chocolate cravings and tastes incredible with a scoop of sugar free ice cream or a dollop of whipped cream.
If you are looking for a quick low carb dessert, this recipe is one to try!
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🌟 Why You'll Love This Recipe
- Fudgy and gooey
- Ultra chocolatey
- Easy - only 6 ingredients
- Quick - cooks in 60 seconds
- Sugar-free and keto friendly - 5.6g net carbs
- Dairy-free
- Egg free
- Gluten-free
Ingredients
Here are the ingredients you'll need for a keto mug brownie recipe:
Peanut Butter - Must be runny and smooth. This is absolutely essential! Hard peanut butter will result in a dry brownie. I like to use brands that are 100% peanuts. You can also use almond butter or any other nut or seed butter.
Coconut Flour - Can be replaced with 3x the amount of almond flour.
Unsweetened Cocoa Powder
Powdered Sweetener - I used a powdered erythritol monk fruit sweetener blend. Pure erythritol, allulose, Swerve or Bocha Sweet also work.
Milk - Any nut or seed milk of your choice. I used almond milk.
Baking Powder - To give the brownie a nice lift.
Optional: Pinch of Salt - Either stir it into the brownie batter or sprinkle a few flakes over the top. You can also add a few drops of vanilla extract.
Optional: Sugar Free Chocolate Chips - Lily's is a popular brand. Or simply chop up a square of 90% dark chocolate such as Lindt.
Instructions
This section contains step-by-step instructions and photos that show how to make this recipe. See the recipe card for full information on ingredients and quantities
- Get a mug.
The "mug" can be any microwave-safe mug or bowl such as a ramekin. My ramekin had a diameter of 3 inches. Option to lightly grease it to prevent sticking.
2. Mix the batter.
In a small bowl, stir together the dry ingredients with a fork. Break up any clumps.
In another small bowl, whisk the nut milk and the peanut butter.
Then, add the dry ingredients to the wet and stir until a brownie batter forms.
Last, fold in the chocolate chips and fill the batter into the prepared mug or ramekin.
3. Microwave.
Microwave the keto mug brownie until it is done. That's it!
Top Tip
I first tested the brownie after 45 seconds. For all of you who like theirs super fudgy, this may already be enough.
Also, keep in mind that mug cakes continue to cook in the hot cup after microwaving.
So, don't be tempted to overcook! Add increments of 10 seconds if necessary.
Microwave Timings
Microwave timings will vary according to the wattage of your microwave. Mine operates at 900 Watt.
Below are suggested timings for different power strengths:
- 600W = low power. 80 seconds
- 800W = 70 seconds
- 900W = 60 seconds.
- 1000W = 50 seconds
- 1200W = 35-40 seconds
Recipe FAQs
Choose a mug, bowl or ramekin that is wide rather than narrow and tall. Never fill it more than ⅔. Always have a few fingers of space at the top. The batter rises as it cooks and can overspill.
Yes. To make a keto brownie mug cake in the oven, bake at 180C (160C fan) / 350F for around 9 minutes. The less you bake it, the fudgier it will be.
Yes. Air fry at 170F / 320F for around 7 minutes.
Use 2 tablespoons of almond flour instead of the coconut flour.
Any seed or nut butter can be used, such as almond butter.
Variations and Substitutions
Below are a few ideas how you can change the flavor:
Caramel swirl brownie: Stir in a swirl of sugar free caramel sauce.
Raspberry brownie: Press a few fresh raspberries into the batter.
Add an egg: This makes it fluffier, with a cake-like texture.
Mocha: Swap out 1 tablespoon of the almond milk with strong coffee. Or, add ¼ teaspoon coffee extract.
Nuts: Add walnuts or pecans into the batter.
Storage
Since this keto brownie in a mug is a single serve recipe, you will probably eat it straight away.
It is possible to store it in the fridge for up to 5 days though. Store in an airtight container.
You can even freeze it for up to 3 months. Defrost overnight.
Related Recipes
Tried this recipe? Give it a star rating below!
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Recipe
Sugar Free Mug Brownie
from Sugar Free LondonerNote: The servings slider only changes the first amount in each line and not any subsequent amounts. Please make your own calculations where necessary.
Equipment
- microwavable mug or ramekin
Ingredients
- ½ tablespoon coconut flour
- 1 tablespoon cocoa powder unsweetened
- 1 tablespoon powdered sweetener
- ⅛ teaspoon baking powder
- 1.5 tbsp peanut butter must be smooth and runny
- 3 tbsp almond milk or any nut or seed milk
- 1 tablespoon sugar free chocolate chips optional
- pinch of sea salt optional
Instructions
- Lightly grease a microwavable mug or ramekin (3 inch diameter).
- I a small bowl, stir together the coconut flour, cocoa powder, baking powder, sweetener and optional pinch of salt with a fork. Break up any clumps.
- In another small bowl, combine the nut milk and the peanut butter. Then, add the dry ingredients to the wet and stir until a brownie batter forms.
- Last, fold in the chocolate chips and fill the batter into the prepared mug or ramekin. Microwave on high for 60 seconds (900W). See suggested microwave timings in the notes below.
Notes
- 600W = low power. 80 seconds
- 800W = 70 seconds
- 900W = 60 seconds.
- 1000W = 50 seconds
- 1200W = 40 seconds
Lai
Yummy
Jami Bonifas
OMG - Beyond decadent and delicious!
Julie
I was very skeptical of trying this brownie in a mug, I have tried SO many and I'm always disappointed. Too sweet, aftertaste, weird texture, etc.. but this one she nailed it for me!
The ingredients are in perfect order, perfect amounts and it's just lovely! The most delicious brownie in a mug I've ever tasted, with a delightful texture. I was not disappointed!
I need not look further and I know my granddaughters will love it too! Yay, thank you Katrin!
Binnur
So good
Karen
This was super easy and really delicious recipe was spot on for 40 seconds! Thank you!!
Colin Gummer
Thank you so much for this recipe! And all the single-serve microwave desserts, for that matter - I'm the only one in my household who eats keto, so it's super helpful to have these on hand when all those around me are addicted to sugar.
I've made this one twice with coconut flour, and just tried it with lupin flour - happy to report it worked perfectly! Straight swap.
Red
I tried this one again just now and put a little extra sugar free sugar in it as I'm a sweet tooth, and microwaved it for just 40 seconds because the first time I tried it at 60 seconds it was way too hard, but this time, the sweetness was perfect, gooey and fudgey aswell, I'll definitely be making this again!. What a difference 20 seconds can make!
Hin
Made this today and it was lovely. However do you have this reciepe in grams? How much is 1/8 of baking powder? My one didnt rise as much.
Katrin Nürnberger
I used measuring spoons. If you like baking, it's a good idea to get some. Otherwise, simply use a teaspoon and ballpark it. This brownie is not supposed to rise much, as you can see from my images, since it does not contain any egg.
Jim Craig
Hi Katrin, this looks amazing and simple at the same time. Can I swap the coconut flour for almond flour and the peanut butter for almond butter, please?
I've recently bought your 5 book bundle and thought I'd ease myself in gently. My daughters love brownies!
Thanks in advance and have a lovely evening, all the best - Jim
Katrin Nürnberger
Yes to both. Use around 3x more almond flour than coconut flour. And thank you for your support! Enjoy the cookbooks.
Suni
This was amazing! So delicious! Somewhat miraculous when I have been pretty much avoiding most anything sweet on my Keto eating; 6 months now, reversed diabetes completely and lost the weight I had hoped too! I did make your easy blueberry cheesecake for a few other special occasions! Thanks so very much!
Katrin Nürnberger
Congratulations on reversing your diabetes! You must be so proud of yourself. And I am really happy you enjoyed the mug brownie!
Louise
More of a gooey fudgy pudding than a brownie (you definitely need a spoon).
I wasn't convinced when I got it out of the microwave
But 5 mins later & a big mug of coffee to wash it down, I'm converted . It's a delicious chocolate, sorry CHOCOLATE, fix. I only ate half as it was quite rich for me. It would be good with cream or ice-cream.
Looking forward to trying the lemon mug cake next xx
nina
kan dit ook in de airfryer of oven ipv de microgolfoven 🙂 en op hoeveel graden en hoelang dan 🙂
Katrin Nürnberger
I would go for 180 celsius and about 6-7 minutes.