This easy keto peanut butter mug cake is a deliciously rich and satisfying dessert. It only takes minutes to make.
This chocolate peanut butter mug cake tastes so good. It is packed with peanut flavor and it is gently sweet. It satisfies that peanut butter craving I often get.
I made the recipe several times before it was perfect.
First, I tried a flourless peanut butter mug cake with only 4 ingredients - peanut butter, egg, sweetener and baking powder. This tasted good, but the texture was a bit firm, especially once cooled.
To fluff it up, I added coconut flour and a good measure of heavy cream. These additions give the mug cake a fluffy yet satisfyingly moist crumb. It's like a decadent mini version of my keto peanut butter bread.
Jump to:
Why This Recipe Works
Quick. This mug cake cooks in the microwave in just 90 seconds. The total time to make the recipe from scratch is 4 minutes. We can all wait 4 minutes for dessert!
Low in carbs. One serving is only 3.6 grams of net carbs. The cake is also naturally gluten-free.
Lovely texture. Not eggy or weirdly spongy like so many keto mug cakes. This one tastes like cake.
Doubles up as breakfast. If you leave out the chocolate chips and use almond milk in place of the cream, you've got a delicious, healthy peanut butter mug cake to start the day.
Ingredients
Let's take a closer look at the ingredients for this keto peanut butter mug cake recipe.
- Peanut Butter - I used smooth peanut butter by Meridian, which only contains one ingredient - peanuts. Make sure your peanut butter is soft and creamy. Also, be aware that not all peanut butter is keto-friendly. Always read the ingredients when you shop. Some brands add sugar or inflammatory vegetable oils.
- Egg - You need a medium egg for this recipe.
- Coconut Flour - Sifted
- Sweetener - I used powdered erythritol. You can also use allulose, Bocha Sweet, monk fruit sweetener or stevia. Even granulated sweeteners will work well in the recipe. Mug cakes are forgiving.
- Heavy Cream - Adds moisture
- Baking Powder - To help the cake rise
- Chocolate - Optional. I used chopped 90% dark chocolate by Lindt. You can also use sugar free chocolate chips.
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
Keto mug cakes are simple, and this one is no exception. Here are the basic steps:
1.) Put all ingredients into a mug.
2.) Mix the ingredients with a fork inside the cup.
3.) Stir in the chopped chocolate.
4.) Microwave until the cake is cooked and starts to peel away from the mug.
Enjoy as is or top with sugar free whipped cream, peanuts and shaved chocolate.
Expert Tips
#1 Choose a tall vessel for microwaving. You want to have at least 3 fingers space at the top. Mug cakes rise as they cook. You don't want the batter to spill over the top.
#2 Microwaves have different power levels and some cook quicker than others. Pause the microwave to check after about 50 seconds. If necessary, continue cooking the cake in 10-second bursts, up to 90 seconds in total.
This cooking method will also prevent spillage as you’re giving the cake time to sink back down in between.
#3 The cake tastes best when it is warm.
Recipe Variations
Most of the time, I make this recipe exactly as written. But sometimes I experiment with the flavor and with the ingredients. Here are a few ideas:
- Possible add-ons for are ½ teaspoon vanilla extract or 1 teaspoon cinnamon.
- To make this mug cake dairy-free, use coconut cream in place of the double/heavy cream.
- If you prefer cakes with almond flour, use ¼ cup or 4 ½ tablespoons of almond flour instead of coconut flour.
- Ran out of peanut butter? You can use almond butter or any other nut butter in this recipe.
Recipe FAQs
Yes. If you do not have a microwave, simply cook the mug cake in the oven. Use oven-proof ramekins and bake at 180 Celsius (350 Fahrenheit) for around 10 to 12 minutes.
You can use almond milk or another nut milk in place of the heavy cream.
There are 2 servings in the recipe. I made 1 cake to share. 2. If you don’t want to spoon from the same cup, simply divide the mix between 2 ramekins. The cooking time remains the same.
Storage And Reheating
You can store this keto mug cake with peanut butter in the fridge for up to 3 days or even freeze it for up to 3 months.
If you divide the batter between 2 ramekins and eat one cake straight away and one the next day, I recommend that you refrigerate the second portion as a batter. Then, cook it straight before eating.
It is also possible to gently re-warm a cooled cake in the microwave for around 10 seconds.
More Keto Mug Cake Recipes
- Keto Vanilla Mug Cake4 Minutes
- Keto Mug Cheesecake (Microwave Recipe)8 Minutes
- Fudgy Keto Brownie In A Mug3 Minutes
- Keto Blueberry Mug Cake4 Minutes
Tried this recipe? Give it a star rating below!
★ STAY IN TOUCH on FACEBOOK, PINTEREST and INSTAGRAM for more great food and join my NEWSLETTER for the latest updates and a FREE EBOOK.★
Recipe
Keto Peanut Butter Mug Cake
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.
Ingredients
- 2 tablespoon peanut butter soft
- 1 ½ tablespoon coconut flour
- 1 ½ tablespoon powdered sweetener add an additional ½ teaspoon if you have a sweet tooth
- 3 tablespoon heavy cream or coconut cream for dairy free
- 1 egg medium
- ¼ teaspoon baking powder
- 1 tbsp dark chocolate, chopped or sugar free chocolate chips optional
Instructions
- Mix all ingredients in a tall glass or mug, using a fork. Fold in the chocolate last, if using.
- Microwave on high for up to 90 seconds. Check after 50 seconds and continue with 10-second bursts until the cake peels away from the mug and the centre is cooked.
Brenda
I don't believe in microwaves due to the belief of damaging food at a molecular level. Have you tried heating this in the oven? I would love to try this!
Katrin Nürnberger
I haven't, but it should work. I would put it in at 175C / 350 F for about 10-12 minutes.
Andrew
“2 people sharing”
Ahhahaha, good one!
Katrin Nürnberger
Sounds like you were hungry!!!! 🙂
Peggy
I loved this cake! I have made it with Sugar free chocolate chips and again using some blueberries for a peanut butter and jelly vibe. Both were awesome!
Katrin
I love the idea of using blueberries in it! I’m so glad you like the recipe and that you put your own spin on it
Josh
Don't normally rate recipes, but this one is absolutely amazing. Do delicious!
Katrin
I appreciate your comment! Thank you!
Paula
I made THREE mini waffles in my Dash waffle iron. I dipped the first two in melted butter mixed with sugar free syrup and the third, I lightly toasted and topped with sugar free raspberry jam. It was great both ways!
Katrin
Both variations sound yummy!!
Lee Turnbull
After numerous attempts with all sorts of keto low carb mug cakes this was after the first try a winner boom. Thank you for this recipe. Lee. X
Katrin
That's great! I've got another few mug cakes on my site - just type "mug cake" into the recipe search box at the top of the page - would love to hear what you think of them!
Pamela Donley
Is it possible to substitute Almond flour for the coconut flour and if so, what would be the ratios?
Katrin
You'd roughly need twice as much almond flour as coconut flour.
MALLORY BEAVER
This was delightful! We also made a peanut butter icing with swerve and heavy whipping cream. I felt like I was cheating!
Katrin
That icing sounds amazing!!!!
Sophia
Absolutely delicious. I couldn't believe how easy and quick it is to make a cake in the microwave!
Gabriella Romer
This recipe is amazing! So moist and soft... I've made it three days in a row now 🙂