There’s something about the afternoon lull that makes you want to reach for a little something sweet — but not just any sweet. It needs to be fast, satisfying, and won’t leave you regretting it later. That’s where this keto banana nut mug cake comes in. It’s a small, cozy cake you can whip up in just a few minutes, right in your mug, without breaking a sweat or digging out a bunch of fancy tools.
One afternoon, I remember pulling out half a banana from the back of the fridge, a little too ripe and begging to be used. I wasn’t exactly planning to bake, but I thought, why not? I tossed it in a mug with a few pantry staples, then microwaved it while I scrolled through my phone. The smell of cinnamon and warm banana filled the kitchen — it was like a mini escape. I almost burned my tongue because I was too eager to dive in, but that first bite was soft, nutty, and just sweet enough. It felt like a tiny reward after a long day, and honestly, I’ve been making it whenever the craving sneaks up since then.
Why You’ll Love It:
- It’s quick — from mixing to mug to mouth in under 10 minutes, perfect for when you want dessert now.
- The texture balances soft banana and crunchy walnuts, giving you that homemade feel without the fuss.
- Keeping it keto-friendly means you get a sweet treat without the carb crash later.
- It’s simple — and that’s kind of the point. No complicated steps or weird ingredients.
- Just one mug to wash afterward. Small victories count.
If you’re a bit wary of mug cakes because they sometimes dry out or come out rubbery, this one surprises you. It’s moist, tender, and keeps that banana flavor front and center. You might need to test your microwave’s timing a bit — I usually start with 90 seconds and add a few more if it’s still jiggly in the middle.
Print
Keto Banana Nut Mug Cake
- Total Time: 7 minutes
- Yield: 1 1x
Description
A quick and easy keto-friendly banana nut mug cake that’s moist, flavorful, and perfect for a low-carb dessert or snack.
Ingredients
1 tablespoon unsalted butter, melted
1 large egg
2 tablespoons mashed ripe banana (about 1/4 of a medium banana)
2 tablespoons almond flour
1 tablespoon coconut flour
1 tablespoon erythritol sweetener
1/4 teaspoon baking powder
1/4 teaspoon vanilla extract
1/8 teaspoon ground cinnamon
2 tablespoons chopped walnuts
Instructions
In a microwave-safe mug, whisk together the melted butter and egg until well combined.
Add the mashed banana and vanilla extract to the mug and mix thoroughly.
Add almond flour, coconut flour, erythritol, baking powder, and ground cinnamon to the mug. Stir until the batter is smooth and evenly mixed.
Fold in the chopped walnuts gently.
Microwave the mug cake on high for 90 to 120 seconds, or until the cake has risen and is set in the middle. Cooking time may vary depending on your microwave wattage.
Carefully remove the mug from the microwave and let it cool for 1 to 2 minutes before eating.
- Prep Time: 5 minutes
- Cook Time: 2 minutes
Kitchen Notes: I usually just grab a regular coffee mug — nothing fancy — and it works perfectly. This cake pairs well with a dollop of whipped cream or a sprinkle of extra chopped nuts if you want to dress it up. Sometimes, I swap walnuts for pecans or add a pinch of nutmeg for a slightly different warmth. If you’re feeling adventurous, a few sugar-free chocolate chips folded in before microwaving make it extra indulgent, though I haven’t tested if that changes cook time much. Just keep an eye on it.
FAQ:
Can I make this without banana? The banana adds moisture and natural sweetness, so leaving it out might make it dry. You could try a bit of unsweetened applesauce, but it’s not quite the same.
How do I store leftovers? I usually eat mine right away, but if you have any left, pop it in an airtight container in the fridge for up to two days and reheat briefly in the microwave.
Is this really keto-friendly? Yes, thanks to almond and coconut flours and erythritol, it keeps carbs low while still tasting sweet.
Give it a go next time you need a quick, cozy fix — you might find it becoming your go-to small treat.