This keto blueberry mug cake recipe is a fluffy single serve cake that cooks in just one minute. It is perfect for those times when you want a simple and quick dessert.
Do you know that time in the afternoon when you sit down with a cup of tea or coffee and think - wouldn't it be nice to have a sweet treat now?
Well, that's exactly where this gluten free, sugar free mug cake comes in. It's a variation on my vanilla mug cake, which I customised by adding a super fruity blueberry centre.
It tastes like keto blueberry muffins, but in a mug - a keto blueberry mug muffin!
Jump to:
What is a mug cake?
In case you've never made a mug cake before, let me explain: A mug cake is a single serve cake in a mug, cup or ramekin. It requires only a few minutes prep and cooks in the microwave.
Using an egg and baking powder makes a microwave cake rise and become fluffy.
Are blueberries keto friendly?
Blueberries are a good choice of fruit when you're on a keto diet. Berries are low in net carbs, bursting with antioxidants and contain high amounts of vitamin C and fiber.
Read this article to find out all about the health benefits of blueberries!
Ingredients
You only need 8 simple ingredients to make this low carb mug cake. Here they are:
- Almond Flour - Both ground almonds and super fine almond flour work well.
- Coconut Flour - You need this nut free, gluten-free flour for extra stability.
- Butter - Substitute with coconut oil for a dairy free version.
- Egg - Use a medium egg if using regular almond flour and a large egg if your almond flour is super fine.
- Sweetener - I used a granulated erythritol monk fruit sweetener blend. However, you can use allulose, xylitol, Bocha Sweet, Swerve or pure erythritol.
- Vanilla extract (or use 1 teaspoon lemon juice and lemon zest!)
- Baking powder - Make sure it is fresh.
- Blueberries - I used 10 fresh berries.
It's important to level the tops of all tablespoons when measuring.
My top tip
I like to dust my blueberries in coconut flour before adding them to the batter. Coconut flour is very absorbent and it prevents the blueberries from sinking to the bottom of the mug.
I pressed my blueberries into the middle of the cake, because I wanted to create a soft blueberry centre.
You can also stir them into the batter like you would for a blueberry muffin.
Instructions
This section contains step-by-step instructions and photos that show how to make this recipe. See the recipe card for full information on ingredients and quantities.
1. Stir together the dry ingredients in a small bowl - almond flour, coconut flour, baking powder, sweetener. Take care to break up any lumps.
2. In a second bowl, whisk the egg. Then add the melted butter plus the vanilla extract and whisk all wet ingredients until combined.
3. Now, add the dry ingredients to the wet and stir until a smooth batter forms.
4. Grease a mug or ramekin with butter and fill in the batter. Press the blueberries into the centre, leaving a little gap at the top. Microwave for 80 seconds at 900 watts.
Serving suggestion
Depending on whether you want to impress or not, enjoy the microwave cake straight from the mug or invert it onto a plate.
Here are topping ideas:
- Dust with powdered sugar
- Add a dollop of whipped cream
- Add a spoonful of sugar free blueberry jam
- make a low carb cream cheese frosting
Microwave timings
I have a 900 watt microwave and my cake took 80 seconds to cook. Here's a quick overview of recommended baking times for this mug cake recipe:
- 600W = low power. 100 seconds.
- 800W = 90 seconds.
- 900W = 80 seconds.
- 1000W = 70 seconds
- 1200W = 60 seconds.
After these times, check whether the cake is done. If it's still undercooked, add increments of 10 seconds.
FAQs
Yes, you can! Preheat the oven to 180C / 350F electric or 160C / 320F fan assisted. Bake for 12-15 minutes or until a skewer or toothpick inserted comes out clean with no crumbs sticking.
Yes. Set the temperature to 160C / 320F and check for doneness after 10 minutes.
If you fill the cup or ramekin to the top with batter, it will overflow and create a mess. Therefore, choose a cup that holds a minimum of 200ml.
You want to have at least 2 fingers of space at the top so the cake can rise.
Yes. Rinse and pat the berries dry, then proceed as per recipe.
Variations
Use other berries: Raspberries, blackberries or even cubed strawberries. And if you feel like something different, use sugar free chocolate chips!
Nut free: For a coconut flour version, omit the almond flour and use 1 â…” cups of coconut flour instead.
Vegan option: Replace the egg with a flax egg made from 1 tablespoon flax and 2.5 tablespoons almond milk.
Storage
Mug cakes are best eaten straight away. They have a tendency to turn dense if left for a couple of hours.
It is possible to store it in an airtight container in the fridge for up to 2 days if necessary.
You can also freeze it for up to 3 months. Defrost overnight, then gently warm in the microwave.
Related recipes
Here are some more of my microwave cake recipes. I can't decide which one I like best!
Tried this recipe? Give it a star rating below!
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Recipe
Keto Blueberry Mug Cake
from Sugar Free LondonerNote: The servings slider only changes the first amount in each line and not any subsequent amounts. Please make your own calculations where necessary.
Ingredients
- 2 tablespoon almond flour
- 1 tablespoon coconut flour
- 1 tablespoon butter melted
- 1 egg use a medium egg with ground almonds or coarse almond flour and a large egg with super fine almond flour
- 1 tablespoon granulated sweetener
- 1 teaspoon vanilla extract
- ¼ teaspoon baking powder
- 10 blueberries 27g
Instructions
- Stir together the dry ingredients in a bowl - almond flour, coconut flour, baking powder, sweetener. Take care to break up any lumps.
- In a second bowl, whisk the egg. Then add the melted and cooled butter plus the vanilla extract and whisk until combined.
- Now, add the dry ingredients to the wet and stir until a smooth batter forms.
- Grease a mug or ramekin with butter and fill in the batter. Press the blueberries into the centre, leaving a little gap at the top.
- Microwave for 80 seconds (adjust depending on the power level of your microwave. See suggested microwave timings in the notes below).
Notes
- 600W = low power. 100 seconds.Â
- 800W = 90 seconds.
- 900W = 80 seconds.Â
- 1000W = 70 seconds
- 1200W = 60 seconds.Â
Julie
I only have coconut flour right now. Do you think it would work with just that?
Katrin Nürnberger
I recommend that you use the recipe for my coconut flour mug cake.
Becky
I just wanted to thank you so so much! I’m 5 stone down on my keto journey (this is my second attempt) ….on previous occasions when I’ve messed up it’s always been because of sudden sweet tooth cravings and I’ve never been able to find anything quick and easy (apart from a trip to the shops for non keto food!)…..these mug cakes….and this one in particular are my absolute saviour! I literally love them and they seriously kick that craving!!! I’ll be trying even more of your recipes but thank you so much for inventing these, leaving them accessible for people and preventing me sabotaging! Absolutely fantastic
Kate
I love your recipes! I am recently diagnosed with diabetes, so I am counting carbs. However, I need to lose weight too and your lovely desserts are quite high in calories.
Can you suggest any low carb/ low calorie ideas?
Thanks.
Kate
Katrin Nürnberger
Thank you so much for your kind words! Glad you like the website. You can experiment with replacing the butter in my baking recipes with yoghurt (by 50% or even more). That will lower the fat content and therefore the calories significantly. I would also recommend to really focus on eating green vegetables and lean protein, therefore crowding out the stuff that you shouldn't have. Take a look at my Keto Reset Meal Plan, which has helped lots of people lose weight without having to feel hungry.