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90-Second Keto Blueberry Mug Cake

4.65 from 37 votes
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This recipe may contain Amazon or other affiliate links. As an Amazon Associate I earn from qualifying purchases.

This Keto Blueberry Mug Cake is a moist microwave keto cake in a mug ready in 90 seconds to fix all your sweet cravings in no time.

Bonus, one of these keto mug cakes contains only 3.5 grams of net carbs, so you can indulge without maxing out your macros.

Keto blueberry muffin in a mug
Table of contents

What’s A Keto Blueberry Mug Cake?

A keto blueberry mug cake is a keto blueberry cake in a mug, baked in 90 seconds in your microwave.

It’s the best keto snack to fix your cake craving quickly with few carbs, no sugar and is gluten-free.

How To Make A Keto Blueberry Mug Cake

This recipe makes two moist keto muffins baked in a mug.


To make this easy keto mug cake recipe, you need:

  • Large egg – yes, eggs are keto!
  • Almond flour – use ultra-fine almond flour with a golden color. If you prefer to use coconut flour, use my coconut flour mug cake recipe and add blueberries to the batter.
  • Erythritol or any keto sweetener you love.
  • Unsweetened almond milk – because regular milk is high in carbs.
  • Baking powder
  • Vanilla extract
  • Blueberries – fresh or frozen and an extra 1/2 teaspoon of coconut flour to roll the keto-friendly berries and prevent them from sinking to the bottom of the coffee mug.

Combining Dry And Wet Ingredients

In a small bowl, beat egg, almond milk vanilla. Then, stir in baking powder, almond flour, and erythritol until a thick batter forms.

In another bowl, stir the blueberries with coconut flour. This is optional, but it prevents the blueberries from sinking to the bottom of the mug.

Fold in the blueberries and split the keto blueberry muffin batter evenly into two tall coffee mugs.

It is essential to use tall coffee mugs because the muffins will rise and might overflow from the mugs.

How to make keto blueberry muffins IN A MUG

Baking In The Microwave

This recipe is baked in the microwave for a quick 90-second keto snack. To achieve a moist mug cake, you must bake this recipe:

  • One mug at a time – don’t place both mugs in the microwave at once, or they won’t bake evenly.
  • Set the microwave on high powder  800 W-900W.
  • Microwave for 80 seconds first.
  • Keep baking for an additional 10 seconds if it is still wet in the center.


Place one coffee mug in the center of the microwave.

Set the microwave power to high/800W and microwave the keto blueberry muffin mug cake recipe for 80-90 seconds each, until it is set on the top and has doubled in height.

Keto blueberry mug cake

Cooling Down

Remove the low-carb blueberry mug cake from the microwave and cool down 1 minute before eating.

You can eat it in the mug itself or flip it over a plate to cool down quickly.

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Blueberry Mug Cake Toppings

This quick and easy mug cake is delicious topped with:

  • Unsweetened whipped cream
  • Extra blueberries
  • Sliced almonds
  • Powdered erythritol
  • Drizzle peanut butter
  • A dollop of cream cheese


You can create a range of blueberry mug cake flavors by adding some of the below ingredients into the batter:

  • 1-2 tablespoons of sugar-free white chocolate chips.
  • 1-2 teaspoons of chopped almonds.
  • 1 teaspoon of lemon zest.
  • 1/2 teaspoon of lemon extract.
Keto blueberry muffin mug cake

Storage Instructions

This easy recipe for blueberry mug cake serves 2 mug cakes.

To store the extra mug cake batter, place the uncooked batter in a sealed container or into a tall coffee mug and wrap the top with film wrap.

Refrigerate for up to 48 hours. Microwave it just before eating.

You can’t store a microwave-baked mug cake for more than 30 minutes. After that time, the mug cake becomes hard and dense.

Keto blueberry cake in a mug

Frequently Asked Questions

Can I Use Other Berries?

Yes, you can replace blueberries with other keto fruits like strawberries, raspberries, or boysenberries.

Can I Bake This Blueberry Mug Cake?

Yes, you can bake this keto blueberry mug cake. However, the muffins won’t rise as much as seen in the picture.

Preheat the oven to 350°F (180°C). Divide the batter into two oven-proof ramekins, grease with butter or coconut oil.

Bake both ramekins in the center rack of the oven for 15-20 minutes or until a pick inserted in the center of the cake comes out clean.

Why Do Berries Sink To The Bottom Of The Mug?

This happens if you didn’t roll the berries into coconut flour before adding the batter.

Make sure you roll the berries with 1/2 teaspoon of coconut flour to prevent this to happens.

More Keto Mug Cake Recipes

Keto mug cakes are the best to fix your sugar craving and cake craving on a keto diet.

They are quick to make, tasty, and low in carbs. Below I listed my top keto mug cake recipes for you to try:

Have you made these low-carb keto blueberry muffins in a mug? Share a comment or review below. I love to hear your feedback on my recipes,

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Keto Blueberry Mug Cake

Keto Blueberry Muffins in a Mug

3.5gNet Carbs
An easy recipe to make two keto blueberry muffins in a mug in less than 2 minutes.
Prep: 5 minutes
Cook: 2 minutes
Total: 7 minutes
Yield: 2 mug muffins
Serving Size: 1 muffin
4.65 from 37 votes


To prevent the blueberries from sinking in the mug – optional

This recipe may contain Amazon or other affiliate links. As an Amazon Associate I earn from qualifying purchases.


  • In a small bowl, beat egg, vanilla, unsweetened almond milk, and melted coconut oil.
  • Stir in almond flour, baking powder, and erythritol until smooth.
  • In another mixing bowl, stir blueberries with coconut flour. This prevents them from sinking at the bottom of the mug.
  • Fold the blueberries into the batter.
  • Transfer the batter into two tall mug cakes. Your mug cake will rise and double in height so make sure you are using a tall mug, or the batter will overflow.
  • Bake each mug cake in the microwave, one at a time, power 800W for 90 seconds each. Don't microwave both mug cakes at the same time. Note that if your microwave has higher power, you will need to decrease baking time to avoid a dry mug cake. You can start with 80 seconds, check the texture, and return to the microwave for an additional 10 seconds until it is baked through.
  • Cool 2 minutes before serving to avoid burning yourself.
  • Enjoy directly in the mug. Top with unsweetened whipped cream if desired

Baking method

  • Note that baking this recipe won't result in a similar texture. The muffins won't rise as much. Bake at 350°F (180°C) for 15-20 minutes in 2 oven-proofed ramekins.
  • Insert a skewer in the center of the cake to check if it's baked. If it comes out dry, it is baked.


  • You can't store a mug cake baked in the microwave. The texture will be chewy, eggy after 1 hour.

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Nutrition1 muffin
Yield: 2 mug muffins


Serving: 1 muffinCalories: 146.8 kcal (7%)Carbohydrates: 5.3 g (2%)Fiber: 1.8 g (8%)Net Carbs: 3.5 gProtein: 6.3 g (13%)Fat: 11.5 g (18%)Saturated Fat: 3 g (19%)Trans Fat: 0.1 gCholesterol: 93 mg (31%)Sodium: 161.3 mg (7%)Potassium: 46.2 mg (1%)Sugar: 2 g (2%)Vitamin A: 141 IU (3%)Vitamin B12: 0.2 µg (3%)Vitamin C: 1.1 mg (1%)Vitamin D: 0.5 µg (3%)Calcium: 121 mg (12%)Iron: 1.1 mg (6%)Magnesium: 4.2 mg (1%)Zinc: 0.3 mg (2%)
Carine Claudepierre

About The Author

Carine Claudepierre

Hi, I'm Carine, the food blogger, author, recipe developer, published author of a cookbook and many ebooks, and founder of Sweet As Honey.

I have an Accredited Certificate in Nutrition and Wellness obtained in 2014 from Well College Global (formerly Cadence Health). I'm passionate about sharing all my easy and tasty recipes that are both delicious and healthy. My expertise in the field comes from my background in chemistry and years of following a keto low-carb diet. But I'm also well versed in vegetarian and vegan cooking since my husband is vegan.

I now eat a more balanced diet where I alternate between keto and a Mediterranean Diet

Cooking and Baking is my true passion. In fact, I only share a small portion of my recipes on Sweet As Honey. Most of them are eaten by my husband and my two kids before I have time to take any pictures!

All my recipes are at least triple tested to make sure they work and I take pride in keeping them as accurate as possible.

Browse all my recipes with my Recipe Index.

I hope that you too find the recipes you love on Sweet As Honey!

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    7 Thoughts On 90-Second Keto Blueberry Mug Cake
  1. It turned out perfectly but I’ve noticed these kinds of quick microwave keto breads end up tasting a bit too eggy sometimes. I saw something about removing the yolk and just using egg whites. Any suggestions?

  2. 5 stars
    I have been making this recipe for a while and I really love it! However, I usually use fresh berries, and today I used frozen berries and my cake came out way undercooked. How much time should I add if the berries are frozen?

    • You can cover the frozen berries with few teaspoon of coconut flour, the fiber in flour absorb the liquid in the fruit and avoid this to happens. Otherwise you can increase microwave time by 10 seconds burst until cooked in the center.

  3. These mug cakes are so perfect and easy to make for a quick snack or breakfast. Very tasty with some fresh strawberries or blueberries on top !

  4. What size mug(volume) do you suggest? The biggest that I have is 12oz.

    Can I replace the egg with chia egg since I am allergic to eggs? Would I need more baking powder if I didn’t use an egg?

    • The most important is to use a tall coffee mug, 12 oz is fine if it’s tall as a regular coffee mug 95 mm. You can’t make this recipe with egg replacement like chia eggs or any of them, the batter will stay runny and never firm up


The recipes, instructions, and articles on this website should not be taken or used as medical advice. You must consult with your doctor before starting on a keto or low-carb diet. The nutritional data provided on Sweetashoney is to be used as indicative only.

The nutrition data is calculated using WP Recipe Maker. Net Carbs is calculated by removing the fiber and some sweeteners from the total Carbohydrates. As an example, a recipe with 10 grams of Carbs per 100 grams that contains 3 grams of erythritol and 5 grams of fiber will have a net carbs content of 2 grams. Some sweeteners are excluded because they are not metabolized.

You should always calculate the nutritional data yourself instead of relying on Sweetashoney's data. Sweetashoney and its recipes and articles are not intended to cure, prevent, diagnose, or treat any disease. Sweetashoney cannot be liable for adverse reactions or any other outcome resulting from the use of recipes or advice found on the Website.