Have dessert on demand with this delicious oat flour mug cake. Ready in 5 minutes, it is naturally sweetened, gluten free and so fluffy. With both a chocolate and vanilla version in the recipe card, it is sure to satisfy your sweet tooth. Plus, it can also be made with rolled oats if you don't have oat flour on hand.
Jump to:
I started to use oat flour as my go to for baking a few years ago. And I made it my mission to create oat flour versions of all of my favorite baked goods (like chocolate chip cookies and bagels).
Then one day I had a craving for cake. And I wanted cake now. So I wondered about making an oat mug cake.
And it exceeded my expectations (which is saying something because I have high standards when it comes to oat flour recipes!). I'm sure you'll love it because it is:
- Dessert in 5 Minutes. If you're looking for a quick dessert, a mug cake is exactly what you need. Single serve, minimal dishes and ready in minutes, it is there for you for any dessert emergency (they happen 😉 ).
- Better for You Ingredients. While it is a treat, this recipe is made with wholesome oat flour and naturally sweetened with maple syrup for a slightly healthier spin.
- Fluffy Texture. It's almost like magic how fluffy and cake-like this turns out. It truly has the texture of a cake you spent much longer on to make.
- Choose Your Flavor. With both a chocolate and vanilla base recipe, this can be customized to suit whatever you're craving! Want to add chocolate chips, lemon extract or cinnamon? Feel free to get creative.
The Ingredients
- Oat Flour- Instead of making this mug cake with regular flour, the recipe is made entirely with oat flour. If you need the recipe to be gluten free, ensure that you are using certified gluten free oat flour (or oats).
- To Measure Oat Flour: For best results, I always recommend using a kitchen scale. But if you don't have one, lightly pack the oat flour into a measuring cup and then level off (see this Oat Flour 101 post for more info and pictures).
- To Use Rolled Oats Instead: For an oat flourless version, you can substitute rolled oats and blend the batter. You need ⅓ cup + 1 tablespoon of rolled oats (40 grams) in place of the oat flour. Then simply add all of the ingredients to a blender and blend on high until smooth. Pour into your prepared mug and follow the directions for microwaving.
- Water or Milk- It is important not to add too much or the oats won't turn out cakey.
- Egg- This helps to bind the cake. For a vegan version, you can replace with an additional ¼ cup of water though the cake turns out a bit crumblier.
- Maple Syrup- I like to use maple syrup in this mug cake to make it refined sugar free but any sweetener of choice will work (see this list of Maple Syrup Substitutes). You can add more or less depending on your desired level of sweetness.
- Baking Powder- This is what gives the cake it's rise so that it has a fluffy texture. For best results, make sure that yours is fresh.
- Sea Salt- Just a touch balances out the flavors.
- Vanilla Extract or Cocoa- For flavor.
The Method
1. Mix. Add the dry ingredients to a 12 ounce mug and whisk to combine. Add the egg, water, syrup and vanilla (if using) and mix until smooth.
2. Cook. Cook in the microwave on high for 1 and ½ to 2 minutes until the center appears just set. The bake time will vary depending on your mug size and shape as well as your model of microwave.
*Note, the cake puffs up and appears like it might overflow while cooking but it should sink back down once it rests.
3. Rest. For best texture, allow the cake to cool for 2-3 minutes to set.
4. Enjoy!
Leftovers and Storage
The nature of a mug cake is that it is ready in minutes and makes a small batch so I recommend enjoying it fresh and not planning for leftovers. But if you do end up with some leftover, here are storage tips.
To Store: Allow oat mug cake to cool to room temperature and then store in the refrigerator for up to 3 days or freeze for up to 3 months.
To Reheat: If frozen, thaw in the refrigerator overnight. Rewarm in the microwave for 20-30 seconds if desired.
Make it Your Own
- Include protein powder- If you would like to make the mug cake a little more filling, you can reduce the oat flour to ¼ cup (30 grams) and add a heaping tablespoon of your protein powder of choice (10 grams).
- Add extracts- Experiment by replacing the vanilla with different extracts such as lemon, or maple for different flavors. Or add a splash of mint extract to the chocolate version for a chocolate mint cake.
- Give it a Nut Butter Center- Spoon a tablespoon of your favorite nut butter into the center of the batter before putting it in the microwave for a molten center.
- Incorporate mix-ins- Stir in 1 tablespoon of your choice of mix-ins such as:
- sprinkles
- chocolate chips
- chopped nuts
- dried fruit
- shredded coconut
Topping Ideas
- Frosting: If you want to make your mug cake taste extra decadent, you can top it with a little bit of frosting (Maple Cream Cheese Frosting is good on almost anything!). I've also included a quick small batch coconut oil frosting in the recipe card.
- Whipped Cream: Along the lines of decadence, a dollop of whipped cream makes for a delicious touch.
- Fresh Fruit: Try topping it with a handful of fresh berries, banana slices or air fryer apples.
- Nut Butter: Give it a drizzle of peanut butter, macadamia butter or almond butter.
- Yogurt: A dollop of Greek yogurt adds a creamy touch and a bit of protein.
- Jam: You can also spread a spoonful of your favorite fruit jam on top (I love adding strawberry chia jam and Greek yogurt to the vanilla version for a strawberry shortcake inspired treat!).
Yes you can! Similar to my microwave baked oats, rather than stirring the ingredients together, simply add them all to the blender, blend until smooth and then pour into the cup and microwave. Replace the oat flour with ⅓ cup plus an additional tablespoon of rolled oats (40 grams total).
Tips and Notes
- But Don't Underbake. Ensure the cake is fully cooked through by microwaving it until set in the center and allowing to rest for 2-3 minutes to set.
- Check Early. Each microwave model is a bit different so check the cake after 60 seconds the first time that you make it to get a gauge of how long it takes in your microwave. If it's not done, put back in for 30 seconds, check again and then another 15-30 seconds if needed.
- Cook Immediately. Once the ingredients are mixed, cook in the microwave immediately. Otherwise, the batter will soak up the liquid and the texture will be off.
LET ME PLAN YOUR DINNERS! Join my email list and receive My FREE Meal Plan (Including Grocery List!) as a gift>>>
And if you liked this recipe...
...you might also like:
Recipe Card
Oat Flour Mug Cake (Chocolate or Vanilla)
Ingredients
Vanilla
- ⅓ cup oat flour
- ½ teaspoon baking powder
- ⅛ teaspoon fine sea salt
- 2 and ½ tablespoon water or milk of choice
- 1 large egg
- 1 tablespoon maple syrup plus additional to taste
- ½ teaspoon vanilla extract
Chocolate
- ⅓ cup oat flour
- 1 tablespoon cocoa powder
- ½ teaspoon baking powder
- ⅛ teaspoon fine sea salt
- 2 and ½ tablespoon water or milk of choice
- 1 large egg
- 1 and ½ tablespoon maple syrup
Instructions
- Lightly grease a 12 oz microwave-safe mug (or ramekin or bowl).
- Add the dry ingredients and whisk to combine. Then add the wet ingredients and stir until smooth.
- Microwave for 1 and ½ to 2 minutes, checking early, until the center is set and bounces back slightly when pressed.*The cake may puff up as it cooks but will sink back down as it cools.
- For best texture, allow to sit for 2-3 minutes to set.
- Top as desired and enjoy!
Janessa says
This turned out even better than I expected! I'll definitely be making it again soon.