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.
Table of contents
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!
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.
How to make a keto blueberry mug cake
(This section contains step by step instructions and photos that show how to make this recipe. Find the recipe card with ingredient amounts and nutritional information at the bottom of the post.)
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 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 suggestions
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 some 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
My microwave operates at 900W 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
Can I make it in the oven?
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.
It should also be possible to cook this keto mug muffin in an air fryer. For this, I would choose a temperature of 160C / 320F and check for doneness after 10 minutes.
Which mug to use
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.
Can I use frozen berries?
Yes, it's possible to make this keto blueberry mug cake with frozen blueberries. Rinse and pat the berries dry, then proceed as per recipe.
Can I use other berries?
Of course! You could use raspberries, blackberries or even cubed strawberries.
And if you feel like something different, use sugar free chocolate chips!
Nut free variation
For a coconut flour version, omit the almond flour and use 1 ⅔ cups of coconut flour instead.
Storage
Mug cakes are best eaten straight away. They have a tendency to turn dense if left for a couple of hours.
More keto mug cake 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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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. ***As an Amazon Associate I earn from qualifying purchases.
Ingredients
- 2 tbsp almond flour
- 1 tbsp coconut flour
- 1 tbsp 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 tbsp granulated sweetener
- 1 tsp vanilla extract
- ¼ tsp 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.
- 800W = 90 seconds.
- 900W = 80 seconds.
- 1000W = 70 seconds
- 1200W = 60 seconds.
Nutrition
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Fiona says
These were so quick and easy and I already had all the ingredients in my pantry. Turned out great and I'm going to play around with other add-ins. Thanks for such a yummy recipe !
Famke says
Just what I needed. We shared this for dessert last night and enjoyed it very much. I am going to try it with raspberries next time to lower the carbs even more.
Katrin Nürnberger says
Yes, I imagine that would work well too.
Glen says
This came out just perfect! Delicious.
Katrin Nürnberger says
Glad you liked the recipe!
Lynette Roth says
My mug cake came out very dry. How can I fix that?
Katrin Nürnberger says
You need to make sure that you use measuring spoons and not regular spoons. The flours also need to be measured levelled and not heaped. Then, you need to check the power level of your microwave. Maybe it's higher than 900W, in which case you need to decrease the cook time. Hope this helps!
Linda says
What about coconut sugar???
Katrin Nürnberger says
You can definitely use coconut sugar as well. It's not a low carb sweetener, but it will work.