This quick and and easy, low carb, peanut butter mug cake is light and fluffy with great peanut butter flavor. Just 6.8 net carbs per generous serving. Top it with your favorite low carb topping or just powdered sugar-free sweetener. It’s definitely big enough to share!
For this recipe you’ll need: almond meal, sugar free sweetener (Swerve), monk fruit or stevia works well, baking powder, baking soda, cream of tartar, egg, butter, peanut butter, club soda, and vanilla syrup.
If you are in a hurry click here to go to the recipe.

You know what kicks my butt when it comes to low carb eating?
Sweets. Cake, candy, cookies… oh my! And it’s not like I am single and can just keep them out of the house! I have a houseful of skinny kids with gargantuan sugar cravings. My husband, who is Type 1, keeps M&Ms in his nightstand in case his blood sugar tanks during the night. I can’t get away from carbs even in my own bedroom!
It’s not too bad during the day when everyone is at work or school but now school is out and I am going to have all of that snacking happening right in front of me. I knew I was either going to make low carb snacks that were good enough to keep me away from the kids’ sweets and the husband’s stash OR I was going to have a hind-end the size of Texas by the time summer was over.
I prefer the former.

So, since I love peanut butter I came up with this peanut butter mug cake. Serves one or two, depending on how hungry you are. It’s a BIG, filling cake. I ate the whole thing but I promise you my stomach is done for the day and it’s only 2 -o-clock. You might want to make it in two mugs if your mugs aren’t huge. I didn’t have a mug that I liked for the pictures so I used a ceramic tart pan. It’s about 6-inches across and 2 1/2-inches deep. It holds a cup of liquid.
If your mugs are on the small side I’d use two of them the first time you make this just to make sure that it doesn’t cascade over the sides in the microwave. It’s also a good idea to put the mug on a plate to catch any possible overflow. If you use 2 mugs cut the cooking time down to about 20 seconds.
I like this just with a dusting of powdered sweetener but it would be amazing with my low carb chocolate spread or caramel sauce.

Here’s that low carb peanut butter mug cake recipe!

Table of Contents
Peanut Butter Mug Cake
Ingredients
- 1/3 cup almond flour
- 1 tablespoon sugar free sweetener
- 1/2 teaspoon monkfruit powder or equivalent Stevia
- 1/2 teaspoon baking powder
- 1/4 teaspoon baking soda
- 1/8 teaspoon cream of tartar
- Pinch of kosher salt
- 1 egg
- 2 tablespoons butter
- 1 tablespoon peanut butter
- 2 tablespoons club soda
- 1/4 teaspoon vanilla extract
- Butter for greasing mug
Instructions
- Grease the mug with a light coating of butter.
- Melt the butter on the stove, watching carefully until it turns a golden brown. If it gets too dark it will be bitter.
- Let cool to room temperature.
- Mix the almond flour, sweeteners, baking powder, baking soda, cream of tartar, and salt in a bowl.
- Blend in the egg, butter, peanut butter, club soda, and vanilla.
- Spoon into the mug.
- Microwave on high for 20 to 30 seconds, or until it is just firm on top. Don’t overcook or it will be dry.
- Remove from the microwave (some shrinkage is normal) and top with your favorite topping.
Hi Marye, great job on the peanut butter mug cake. Wanted to thank you for sharing my recipe low carb cream cheese pound cake. ????
🙂 thanks for stopping by! And yeah.. that cake!! I love pound cake. 😉
So cute!! 🙂
Thanks!
I’m kinda new at attempting to cook low carb. Why the Swerve and the monk fruit?
To sweeten the cake since you can’t use sugar. Using 2 different sweeteners balances the sweetness better, I think.
This looks delicious Marye and would satisfy my peanut butter sweet tooth for sure. I can’t believe just five minutes!!!!
Thank you, Allie!
Mug cakes sure do hit the spot. Never had a peanut butter one. I will have to try soon.
🙂 let me know what you think.