Keto Blueberry Shortcake in a Mug
Published August 7, 2021 • Updated March 2, 2026
This post may contain affiliate links. See my disclosure policy.
This keto blueberry shortcake in a mug takes five minutes and tastes like real bakery cake. Buttery, soft, and just 5g net carbs.
I originally developed this recipe for ChocZero using their vanilla syrup, and I’ve been making it pretty much weekly since then. The syrup adds the liquid that binds everything together, so this isn’t your typical mug cake with eggs and milk. It’s simpler than that, and the texture lands somewhere between a biscuit and a sponge cake.
The first bite is warm blueberry juice soaking into buttery cake, and that’s what keeps me coming back. I’ve tried other blueberry mug cake recipes that use eggs or cream cheese, but they come out rubbery. This one stays soft because the syrup does double duty as sweetener and binder.
If you don’t have vanilla syrup, one reader (Marie) swapped in Greek yogurt with a little extra sweetener. I asked her about the texture and she said it was denser but still good. I’ve since tested it myself and she’s right. The yogurt version is more like a blueberry cobbler than a shortcake, which is its own kind of great.
This is a true single-serving dessert. 5g net carbs for the whole thing, and it takes about five minutes from bowl to first bite. I eat it straight from the ramekin most nights, but if I’m having people over, I flip it onto a plate and add something on top. A keto chocolate mousse alongside it is ridiculous in the best way.
I keep coming back to this for weeknight desserts because there’s no baking time, no preheating, no dishes beyond one bowl and one mug. On days when I want something more involved, I’ll make my birthday mug cake, keto pumpkin dump cake, or keto strawberry shortcake kebabs for a crowd. But for a Tuesday night after dinner, this is the one.
The keto baking community has figured out that almond flour plus a little coconut flour creates the best crumb for mug cakes. Pure coconut flour absorbs too much liquid and goes chalky. Pure almond flour can be too dense. The blend I use here (2 tablespoons each) hits the sweet spot.
One thing I want to flag: the coconut flour matters here. If your coconut flour is old or has been sitting open, it absorbs differently. I’ve had batches come out dry because of stale coconut flour. Fresh, sealed coconut flour makes a noticeable difference in how the batter holds together.
How to Make Keto Blueberry Shortcake in a Mug
Explore 688+ keto recipe videos with step-by-step instructions, tips, and tricks to make keto easy.
Ingredients
2 tablespoons almond flour -
2 tablespoons coconut flour
-
2 tablespoons sugar free vanilla syrup
-
1 tablespoon unsalted butter, melted
-
1/2 teaspoon baking powder
-
pinch of salt
-
2 tablespoons blueberries
Step by Step Instructions
Step by Step Instructions
Make shortcake batter
Mix together almond flour, coconut flour, vanilla syrup, butter, baking powder and salt in a small bowl. Set aside.
Add blueberries
Spray cooking spray into a large ramekin or microwave safe mug. Add blueberries to the dish.
Top with shortcake batter
Scoop shortcake mixture to the top of the blueberries. Microwave for 1 minute. Serve with homemade whipped cream or ice cream.
Nutrition disclaimer
The nutrition information provided is an estimate and is for informational purposes only. I am a Doctor of Pharmacy (Pharm.D.); however, this content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always consult your physician or other qualified health provider before making any lifestyle changes or beginning a new nutrition program.
Your Macros. Your Recipes. Calculated in 60 Seconds.
Get personalized keto macros and instantly see which recipes fit your targets. No more guessing what to eat.
Get My Macros + Recipes →Frequently Asked Questions
Can I use frozen blueberries instead of fresh ones?
I've made this with frozen blueberries plenty of times. Thaw them first and drain the liquid, otherwise your batter gets too wet. The flavor is almost identical to fresh, maybe even a little more intense since frozen berries release more juice when they heat up.
What can I substitute for the almond flour?
I've tested sunflower seed flour as a 1:1 swap and it works great for a nut-free version. The texture is nearly identical. A low carb all-purpose blend works too, but I find the crumb is slightly different. If you go that route, start with the same measurement and add a splash of liquid if the batter seems dry.
What microwave wattage works best for this mug cake?
I use an 800-watt microwave and 60 seconds is my sweet spot. If yours runs hotter (900-1000 watts), start at 45-50 seconds. I overcooked this exactly once at high wattage and the whole thing went rubbery. Underdone is always better than overdone with mug cakes.
How do I know when the mug cake is done?
I stick a spoon in the center. If it comes out clean or with just a few moist crumbs, it's ready. The top should look set and slightly springy. I pull mine when it still looks a tiny bit wet on top because it keeps cooking for another 20-30 seconds from residual heat.
How do I prevent the blueberries from sinking to the bottom?
I toss my blueberries in a pinch of coconut flour before dropping them in the mug. The light coating gives them something to grip so they stay suspended in the batter instead of settling. This works with both fresh and thawed frozen berries.
Can I add lemon zest or juice to this recipe?
I do this all the time. A tablespoon of fresh lemon juice and a teaspoon of zest turns this into a lemon blueberry version, and it's fantastic. The citrus cuts through the sweetness and makes the blueberry flavor pop even more. I add both directly to the batter before spooning it over the berries.
Can I double this recipe to make two servings?
I just make two separate mugs instead of doubling into one larger dish. A bigger volume doesn't cook evenly in the microwave, so you end up with raw spots in the middle. Two mugs side by side, 60 seconds each, and you're done. I do this when my husband wants one too.
Shortcake was the one thing I actually mourned giving up when I started keto last January. Not cake, not cookies. Shortcake. The kind my mom made every summer with whatever fruit was around. I threw this together one evening on a whim, figuring it'd be "fine for keto," and then it was better than fine. The blueberries go jammy from that one minute in the microwave. The crumb came out soft and buttery in a way I wasn't prepared for. I sat eating it out of the ramekin thinking about my mom's kitchen. Sounds dramatic, I know. Trying raspberries next time and I already know it's going to get me the same way.
My grandmother made blueberry shortcake every summer from whatever came out of her garden. I stopped thinking about it when I went keto. Made this last week, one minute in the microwave, and watching the blueberries bubble up hit me out of nowhere. Not the same recipe, but close enough.
That blueberry bubble is my favorite part of this whole recipe. Close enough from a mug counts.
Came in skeptical about coconut flour in a mug, left wanting a second one. Probably the most honest four-star review I can give.
Four stars from a coconut flour skeptic wanting seconds. I'll take it.
Made this on a Tuesday night when my daughter wanted something sweet after dinner. She finished the whole thing before I could even get a spoon in, then immediately asked if we could make two next time. The blueberries soften into the cake in that one minute and you get these little warm pockets all the way through. I'd add an extra tablespoon of blueberries, but that's just me.
She didn't even wait for a spoon. Extra tablespoon works. Toss them in a pinch of coconut flour first so they don't all sink to the bottom.
Used frozen blueberries because I didn't have fresh, and they release enough juice while cooking that you get this little syrupy pool under the cake. Thaw them for a minute first though or the batter takes longer to set in the middle.
That syrupy pool is the whole argument for frozen. Thaw tip is solid - center needs the extra time to catch up.
Used frozen blueberries since that's what I had, thawed with a squeeze of lemon juice before layering in. They released enough liquid during the microwave minute that there's a jammy pocket at the bottom. Didn't plan it, not complaining. The shortcake stays dry and slightly cakey on top while the blueberries underneath go saucy and warm. Two textures, one mug. My microwave runs hot so I pulled it at 50 seconds and the texture landed right. The lemon sharpens the blueberry flavor enough that it tastes like something you'd actually serve.
Lemon with frozen blueberries does something fresh can't quite replicate. And yeah, 50 seconds if your microwave runs hot - I've overcooked this at 60 and the whole thing goes rubbery fast.
Made a batch of these for spring book club and the one woman who always brings the fancy bakery box kept looking at me like I'd been holding out on her.
Tough crowd. If she only knew it was five minutes in a microwave.
Tried frozen blueberries straight from the bag and they actually work better than fresh. Enough juice cooks out to keep it from drying out. Don't even bother thawing.
Huh. I've been telling people to thaw and drain but the batter's small enough that extra juice probably helps more than it hurts. Testing this.
Made a round of these for a girls' night last weekend as a little dessert-in-a-mug moment between courses, mostly because I could pull them together in under five minutes. My friend who has been on the fence about keto desserts picked hers apart looking for the catch, then quietly made herself a second one when she thought no one was watching. The blueberries at the bottom get almost jammy in the microwave, which I think is what got her. Keeping this one in the back pocket for whenever I need something that looks more intentional than it actually is.
The secret second mug tells you everything. Nobody sneaks back for something they're just tolerating.
One minute in the microwave and somehow the blueberries cooked into this little jam pocket at the bottom, first mug cake I've ever tried and I'm already wondering if it works the same with raspberries.
Raspberries work even better. Softer berry, more of that jam effect.
I've made this like five or six times now and I just figured out why mine kept turning out inconsistent (I'm still pretty new to all this keto baking stuff). The times I used frozen blueberries straight from the freezer, the juice kind of pools down into the shortcake as it cools and oh my god it's so much better? Like it makes this little blueberry puddle at the bottom that the shortcake sits in and I didn't even know I wanted that. I was using fresh blueberries the first few times and they're fine but now I always keep a bag of frozen in the back of my freezer just for this. The one minute cook time still works even with frozen berries, which I wasn't expecting. Going to try this with frozen raspberries next because I feel like that would be incredible.
Not draining creates the puddle on purpose now. I tell people to drain because wet batter is a real problem, but the jam pool at the bottom is actually better. Frozen raspberries next, yes.
Pre-mixed the dry ingredients into zip bags on Sunday. Now it's just butter, syrup, and blueberries when the craving hits. Under two minutes.
Stealing this. Late night craving hits and I don't want to be measuring coconut flour at 10pm.
I've written off every keto mug cake I've tried for texture, but this one actually has that dense shortcake crumb. First one I've made twice.
The coconut flour is doing that. Most mug cakes are just almond flour and the texture never lands right. That combo is the whole reason this one works.
Made this recipe using greek yogurt instead of vanilla syrup. Delicious! Added a few teaspoons of sweetener too.
Greek yogurt instead of the syrup. How was the texture? I could see that working but it'd be more dense than the original.
Is this recipe complete? It doesn’t list any liquids. Usually at least an egg or two is needed to make the cake. Also, is it 2 tablespoons of coconut flour or teaspoons? Usually much less coconut flour is needed, which is why I asked.
This is a recipe I developed for ChocZero. I did accidently put in monkfruit sweetener instead of the ChocZero vanilla syrup as the sweetener but I have changed that to make up for more liquid. You can watch this video to see that it has plenty of liquid. https://youtu.be/lkrVU_thXOY