Easy Keto Nut Free Low Carb Sugar Free Lemon Mug Cake
This easy keto Sugar Free Lemon Mug Cake is low carb, nut free, gluten free, and a single serving for perfect portion control! Just 3 grams net carbs!
Easy Keto Lemon Mug Cake
There is just something about tangy lemon flavor that feels like hope in dessert form. Bright. Fresh. Clean. Even in the dead of winter here in New England, the smell of lemon instantly reminds me that spring will come again.
This Sugar-Free Lemon Mug Cake is one of those recipes I keep coming back to year after year, (first published in March 2015)—especially when I want a single serving sweet treat without leftovers calling my name from the counter.
It’s also one of the easiest recipes the next time you are craving a lemon dessert!
It’s:
- Low carb and keto diet friendly
- Gluten free, grain free, and nut free
- Made with coconut flour (not almond flour)
- A true single serving with built-in perfect portion control
- Just 3 net carbs per serving
It’s the easiest way to satisfy a sweet tooth without blowing your goals.
Why Lemon Has Always Been My Go-To
I’m a lemon lover—always have been.
Lemon in my water, lemon in my seltzer and in lemon recipes as much as possible.
Sugar-Free Frozen Lemonade, this Strawberry Lemon Sorbet, and these delicious No Bake Lemon Cheesecake bars have been reader favorites for years.
But lemon is also personal for me.
When my throat feels scratchy or sore, I’ve literally taken the juice of an entire lemon as a quick shot. It might sound intense, but it works better for me than anything else I’ve tried. Lemon has always symbolized healing, freshness, and getting back on track—especially during cold, snowy months.
This mug cake was born out of that same mindset: something comforting, simple, and supportive.
The Testing Behind This Recipe
Before this recipe ever went live, I tested it four different times.
- Coconut flour only
- Coconut flour with flaxseed
- One egg vs two eggs
- More lemon juice vs less lemon juice
I was looking for fluffy texture, not rubbery. Moist, not dry. Lemon-forward but not overpowering.
This version is the winner.
Even if you think you don’t like coconut—trust me—the coconut flavor is not noticeable here. The lemon is the star. My youngest, who hates coconut in every form, absolutely loved this.
Sugar-Free Lemon Mug Cake Ingredients
Dry Ingredients
- Coconut flour
- Baking powder
- Pinch of salt
Wet Ingredients
- Egg
- Fresh lemon juice
- Heavy cream (or coconut cream)
- Lemon liquid stevia
Using coconut flour is essential here. Almond flour cannot be swapped evenly—the texture will not work.
Coconut Flour & Allergies: Let’s Clear This Up
I get this question almost daily.
Is coconut a tree nut?
Botanically speaking, coconut is actually a fruit (a drupe, like a peach with a pit). While the FDA classifies coconut as a tree nut for labeling purposes, it is not a botanical nut.
My own son was diagnosed with a peanut and tree nut allergy at age two. He has safely eaten coconut for years without issue.
That said, if you have allergies, always check with your allergist.
The American College of Allergy, Asthma & Immunology explains that while coconut reactions are possible, most people with tree nut allergies tolerate coconut just fine.
Why This Is the Perfect Mug Cake
This is one of those low carb mug cakes that actually works:
- Uses a microwave-safe mug or small ramekin
- No fancy equipment
- No leftover cake sitting on the counter
- Ready in about 1 minute of cooking time
It’s ideal for anyone following a low-carb lifestyle, ketogenic diet, or anyone simply wanting better portion control.
Easy Lemon Mug Cake Frequently Asked Questions
Can I make this dairy free?
Yes. Swap the heavy cream for canned coconut cream.
Can I use a different low-carb sweetener?
Absolutely. Use any low-carb sweetener you prefer. If you need help adjusting amounts, my Sweetener Guide & Conversion Chart makes it easy.
What size ramekin should I use?
A 7-ounce ramekin works best. You can also divide the batter into two smaller ramekins for 2 single servings of this sugar-free mug cake.
Can I bake this instead of microwaving?
Yes.
- Preheat oven to 350°F
- Bake for 10 minutes or until a toothpick comes out clean
What’s the frosting shown in the video?
That’s my sugar-free vanilla buttercream frosting—totally optional but delicious.
Why I Still Love This Recipe Years Later
This recipe may be simple, but it represents everything I believe in now more than ever:
- No all-or-nothing thinking
- No white-knuckling through cravings
- Simple recipes that support long-term health
Sometimes the best dessert is the one that lets you enjoy a few bites and move on—satisfied, not spiraling.
And if you’re someone who loves lemon as much as I do, this one never disappoints.
More Keto Mug Cake Recipes
More Sugar Free Lemon Recipes: Lemon Cheesecake Mousse, Lemon Custard Pie, Crock Pot Lemon Blueberry Cake.
Other Low Carb Recipes You Might Like:
- 1 Minute Sugar Free Chocolate Mug Cake
- Pumpkin Chocolate Chip Mug Cake
- Red Velvet Couples Mug Cake
- Carrot Cake Mug Cake
Need help meal planning? My weekly Midlife Macro Meal Plans are available each week using all my recipes for low-carb meals, and snacks.
If you’re following a classic keto diet, this meal plan works for both low carb, midlife and classic keto approaches, sent directly to your inbox. Easy meals each night of the week! Shopping list is done for you! Want a sample plan?
Sugar-Free Lemon Mug Cake
Ingredients
- 1 egg
- 2 tablespoons lemon juice and lemon zest optional
- 2 tablespoons heavy cream
- 1/2 teaspoon lemon liquid stevia or 1/4 cup low carb granular sweetener
- 2 tbsp coconut flour
- 1/4 teaspoon baking powder
- pinch salt
Instructions
- Whisk the egg, lemon juice, cream and stevia together in a small bowl.
- Stir in the coconut flour, baking powder and salt.
- Pour batter evenly into two 7 ounce ramekins or or 1 microwave-safe mug or bowl.
- Microwave 1 minute then in 30 second intervals for each lemon cake or until toothpick in center comes out clean.
- Top with sugar free whipped cream if desired!
Oven instructions
- Preheat your oven to 350 degrees F. Bake for 10 minutes or until a toothpick in center comes out clean.
Video
Notes
Nutrition
About Brenda
Brenda Bennett is a certified Nutritional Therapy Practitioner, certified Sugar Detox Coach, certified Keto Coach, and certified Life Coach. She has been Sugar Free & refined-carb free for 20 years and is the author of four cookbooks: Sugar-Free Mom, Naturally Keto, The 30-Day Sugar Elimination Diet, and her newest release, Good, Better, Best (2025). Her work focuses on helping women detox from sugar, eliminate cravings, balance blood sugar, and lose weight while enjoying delicious, nutrient-dense whole foods. Brenda is also the creator of the Midlife Macro™ Method and the weekly Midlife Macro Meal Plans™, designed specifically for women in perimenopause and menopause who want simple, high-protein, low-carb meals to support hormones, metabolism, and long-term health.She is the founder of the Sugar Free Fresh Start course and the Sugar Free Mom Tribe membership.
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I just made this dessert and it is fabulous. I love the fact that you can make it in under ten minutes from start to finish. I topped it off with homemade whipped cream and fed it to my husband. He loves it. Thanks again for another yummy dessert.
This looks divine!!!!!! I found this recipe on Pinterest and I HAVE to try it! A few questions though, 1) what kind of dish should I use to bake it ? 2) could I use another citrus, such as lime or orange?
I used a 7 ounce ramekin. Yes another citrus is fine.
Just had it, life saver after carb cravings. Thanks for your great recipes.
Can you give me the measurements for using another sweetener. I am not a fan of Stevie and use something that measures cup for cup with sugar. Thanks
Liquid lemon stevia- really? I wish just once I could look at one of these recipes and NOT have to order some obscure ingredient off the internet.
Are you not sugar free? These are regular products in my recipes, liquid stevia mostly. What do you use for a sugar free sweetener? You could certainly use what you have on hand. Here’s my conversion chart:https://www.sugarfreemom.com/recipes/stevia-differences-in-liquid-packets-powdered-pure-a-stevia-conversion-chart/
I tried this today and was very pleased with the results. I did not have the lemon stevia and so used regular liquid stevia and added a bit of lemon extract. I also added a bit of lemon zest. I topped it with whipped cream sweetened with Gentle Sweet and it was divine! I ate the whole thing but honestly, it would easily have made 2 servings. Thanks so much!
I am new to mug cakes and what a great concept as so many times when I make desserts, I am eating them for days because my husband and family prefers sugar desserts. This is great!
This lemon mug cake is delicious. Thank you so much for the recipe.
could I replace the cream with coconut cream? and if I want to bake it – how long?
You can. 350 degrees for 15 min-20min, check in center with toothpick.
What could I use instead of lemon flavored Stevia? I don’t use any flavored Stevias. Thanks
You can use plain stevia that will be fine.
I absolutely love the beautiful pictures you provide of your creations. They are so appealing. So glad to have found you on facebook,.
Thanks so much!
I made this with gluten free flour instead of coconut I used honey instead of stevia and almond milk instead of the heavy cream I really liked it but I like lemon and the tart of lemon bars this was very similar and next time I will add fresh blueberries in there YUM
These look delicious!
I would love to make my little boy one but he has an egg allerggy. Any suggestions on a substitute?
Maybe a flax egg? Sorry I’ve not tried it without the egg.
I made it tonight and it was bitter. Odd after taste. I used liquid lemon stevia sweetleaf just like the instructions said and I couldnt finish it. I loved the texture and concept but am new to going sugar free. I’ve cut sugar out completely from my diet. So I wanted to try a couple of treats now that I’ve been without sugar altogether for a few months now. Is it just something you get used to or should I tweak it a different way.
If it was bitter, you probably needed more than I suggested in the recipe. I’ve been sugar free for 12 years so I don’t taste any bitterness when using stevia. It just might be you need to add more or try another sugar free sweetener like this one:https://www.sugarfreemom.com/recipes/what-is-erythritol-a-swerve-give-away/
I love lemon…I need to make this tomorrow!
This is my first time to your site…thank you for posting all the nutrition facts!
Hello! My microwave does not work. Do you know if this would work to bake in the oven? Let me know. thanks 🙂
I think you could bake it at 350 F for 15 minutes, but i’ve not tried it so keep an eye on it.
This recipe is magnificent. I made one tonight as I was craving a snack and I wanted something a bit sweet. It was absolutely perfect!
My husband is a lemon fanatic. I surprised him with this tonight and he loves it. Thank you for another great recipe.
So happy he liked it!
This was fabulous! I never comment on these things but I had to let you know it was truly delicious 🙂 thank you for sharing .I will be using this often!
Way too sweet for me! Did I read it right? 1/2 teaspoon liquid lemon stevia? I’m going to try it again with a lot less stevia because it is very moist light and easy! Thanks!
depends on which brand of liquid stevia you have. If you are using NuNaturals, it’s much sweeter in comaparison to Sweetleaf.
Just found this and it looks delicious!
i am enjoying this cake right now and it is the BEST MUG CAKE EVER!! it is SUPER moist and decadent. i made a cream cheese frosting and added lemon zest to it. thank you so much. this is now my go-to afternoon snack!
oh and i also used a 1/2 packet of powdered stevia since i dont have any liquid.
Thank you so much!
This is delicious! Very lemony, light & fluffy. I will be saving this one for sure.
I don’t use microwaves anymore, can they be baked in a convection oven?
Can I make this cake without the liquid lemon stevia? I have THM sweet blend and wondered if that would work. I can’t wait to try this ca,e!!
I’m sure you could but I don’t use THM blend so not sure how much you should use.