This easy peanut butter mug cake is fudgy, moist, made in the microwave, and ready in under 5 minutes. Add in some chocolate chips or an extra drizzle of peanut butter on top for the most delicious mug cake recipe.
I can’t say no to a peanut butter treat – and when you’re short on time, then this peanut butter mug cake is the perfect treat. It tastes somewhere in between a peanut butter cookie, and a fudgy piece of cake. It’s super moist and has a delicious peanut butter flavor without being too sweet.
I posted my first mug cake recipe on Just So Tasty only a few months ago. But since then – this vanilla mug cake recipe has been going crazy. So I made the chocolate version next, and since I can’t say no to a peanut butter treat, this peanut butter mug cake recipe had to happen.
How to Make a Peanut Butter Mug Cake 
Mug cakes are so incredible for a few reasons:
- they’re made in the microwave
- they only need a few ingredients
- and are the easiest cake recipes you’ll ever make
For this peanut butter mug cake you’ll need:
- 1 ½ tablespoons oil
- 2 tablespoons peanut butter
- 2 tablespoons sugar
- 1 egg yolk
- 2 tablespoon flour
- ¼ teaspoon baking powder
- 2 tablespoons milk
Add the oil, peanut butter, sugar and egg yolk to your mug and give them a whisk. Gently stir in the flour and baking powder, then whisk in the milk. You can also stir in 1 tablespoon of chocolate chips at this point too. Then to “bake the cake” – microwave for 1 minute and 30 seconds, or until you see the top start to puff up and it looks set on the top. 
How do I make a peanut butter mug cake without egg?
Replace the egg yolk with 1 extra tablespoon of milk. I found that using the egg yolk makes the mug cake extra moist and fudgy, but you can definitely just use milk instead.
Can I turn this into a chocolate peanut butter mug cake?
Absolutely. Simply add in 2 teaspoons of cocoa powder in addition to the flour.
I love this peanut butter mug cake when it’s late at night and I’m craving something sweet. It’s so easy to make, perfectly peanut buttery, and so fudgy and moist.
For more mug cake recipes, don’t forget these favorites:
Or for more easy peanut butter recipes:
- Flourless Peanut Butter Cookies
- 3 Ingredient Peanut Butter Cookies
- Peanut Butter Oatmeal No Bake Cookies
- Peanut Butter Chocolate Chip Cookies
Peanut Butter Mug Cake
Ingredients
- 1 ½ tablespoons oil
- 2 tablespoons peanut butter
- 2 tablespoons sugar
- 1 large egg yolk or 1 extra tablespoon milk
- 2 tablespoons flour
- ¼ teaspoon baking powder
- 2 tablespoons milk
- 1 tablespoon chocolate chips
Instructions
- Add the oil, peanut butter, sugar & egg yolk to a large mug. Whisk together until smooth.
- Whisk in the flour and baking powder.
- Stir in the milk and optional chocolate chips
- Microwave for 1 minute and 30 seconds or until the top looks set.
- Let stand for 1-2 minutes to cool slightly, then top with ice cream or a drizzle of peanut butter.
Fiona,
Wonderful mug cake recipe. It is so moist and fluffy. I will be making this again. It is one of the best mug cake recipes out there. Thanks for sharing.
This mug cake turned out really well! Moist, fluffy, great flavor! I used one Tablespoon sugar and one Tablespoon stevia in the raw, and it was still great! I will be making this again.
It was kinda good but i didnt like the crumblyness. The peanut butter flavor to me isnt really there aswell, but overall the mug cake i ever made 🙂
Made a couple of adjustments, still came out great! I replaced the sugar with erythritol, the flour with almond flour and added chocolate chips. I accidentally added 2 tablespoons of oil so i added a few more teaspoons of almost flour. I eyeballed the peanut butter and it’s probably more then the recipe calls for :)) finally i put it in a small rectangular glass container not a mug, i think it cooks more even like that. I think the secret in this recipe is the egg yolk.
This mug cake was pretty darn tasty. I used the extra crunchy peanut butter it was on point thanks for the recipe.
This is the BEST mug cake!! I love it! Thanks for the recipe!!
I have made a few mug cakes and this one is by far the best I have ever had. Wow wow wow. So delicious.
To be honest, I have a sweet tooth, hence me making smug cake. This cake is not sweet enough. Maybe 3 tablespoons of sugar? I will try that next time.
Great mug cake. This was my version:
11/2 T oil 1/8 tea. vanilla
3 T. Peanut butter
11/2 heap
ing T. White sugar & 1 1/2 T. Packed brown sugar
2 T. Flour
2 tea. Cocoa powder
1/4 tea. Baking powder
3 T. Milk
(Sprinkle white sugar on top)
Microwave for 1 minute & 40 seconds
The cake texture & taste is so satisfying !
Thank you for being a good cook & for SHARING !
So tasty! Probably would have stopped microwaving 15 seconds earlier so it was even more moist but the taste was still there overall really really good
Out of this world! I used ground oat bran 😋😋😋
Overall, this recipe is a win. I made it for my mom and stepdad, and it was a hit. The only thing that was a tad off to me was the texture. It was crumbly and turned into a paste (not a nice feeling) when it went into your mouth. I don’t know if this is just a mistake I made and not really because of the recipe itself. Then again, it was still delicious! Thank you so much for a wonderful recipe! 😉
PS: it took me a while to finally make up my mind for 4 or 5 stars. I just wanted to let ya know it was very close!