Grab a cup and whip up this vegan banana mug cake using oat flour, mashed banana, and no egg needed! So fluffy, moist, and comforting, you’d never guess it’s eggless and dairy free. And made with only 6 ingredients! Learn how to make banana bread in a mug in under 3 minutes in the microwave.

For more of the best gluten free mug cake recipes, try my vegan chocolate mug cake or healthy pumpkin mug cake!

Healthy Banana Mug Cake

Microwave Banana Bread in a Mug!?

If you’ve got a ripe banana at home, now’s the time to give this healthy mug cake recipe a try. You probably have everything else you’ll need already stocked in your pantry! Use oat flour for a gluten free banana mug cake, or you can use all-purpose flour if desired. No eggs at home? No problem! This is the ultimate, eggless single-serving dessert that you can throw together in a pinch.

Rather than baking a whole loaf of banana bread in the oven for an hour, pop this banana bread mug cake in the microwave and chow down ASAP! The same sweet, fluffy satisfaction, for a fraction of the time and effort. And you can maximize the deliciousness with tasty mix-ins and toppings! See how to make a banana mug cake without egg, using nut butter + nondairy milk instead to keep it vegan.

Vegan Banana Mug Cake
How to Make Banana Bread in a Mug

What can I do with extra bananas?

When you’ve got extra ripe bananas at home, an easy banana bread recipe or quick smoothie are the usual go-to’s. Or, you can whip up a healthy banana mug cake in under 10 minutes! A warm and comforting single-serving treat, that’s conveniently cooked in the microwave. It’s as satisfying as a slice of banana bread, without needing to use an oven or any baking equipment!  

What can I use instead of egg in a banana mug cake?

For an eggless mug cake recipe, use a plant-based fat source like nut butter instead of eggs. Eggs provide fat and liquid in a cake recipe, which helps hold the batter together and maintain the cake’s structure. In this vegan banana mug cake with no egg, I used almond butter + non-dairy milk instead of an egg. The result is a rich, flavorful, moist cake that you’d never guess is eggless!

Healthy Banana Bread Mug Cake

Banana Bread Mug Cake Ingredients

  • Oat Flour. For a true gluten free banana mug cake recipe, use oat flour (certified GF) or a gluten free all-purpose flour. This recipe will also work with regular all-purpose flour or wheat flour if you don’t need it to be GF.
  • Baking Powder. Especially since we’re making this banana mug cake without egg, baking powder is crucial to give the cake some rise and fluffiness!
  • Salt. Don’t forget to add a pinch to highlight the sweet, comforting flavors in this recipe.
  • Banana. Mashed banana helps act as a fat substitute in this recipe, while also adding natural sweetness and flavor. Be sure to use a ripe banana for the best flavor, or you can also use banana baby food! If you don’t need/want banana flavor, you could use applesauce, pumpkin, or sweet potato puree instead.
  • Maple Syrup. Just a dash of sweetener will make this healthy mug cake all the more satisfying! Use maple syrup or granulated sugar for a vegan mug cake, or you can also use honey for non-vegan. Granulated low carb sweeteners like stevia or erythritol should also work in this recipe—I’m personally just not keen on how they taste.
  • Almond Butter. You’ll need some type of smooth, salted nut butter to keep this banana bread mug cake eggless. I like almond butter because of its neutral flavor, but you could also use cashew butter or even peanut butter for a salty-sweet banana PB treat!
  • Nondairy Milk. Almond milk is my go-to, but you can also use oat, soy, coconut, cashew milk, etc. (Any dairy milks will work as well.)

Substitution Note: To make your mug cake with egg

If you don’t need an eggless or vegan mug cake, you can also make this gluten free banana mug cake with an egg! Just substitute 1 egg for the nut butter + milk, and microwave ~15-20 seconds less. When I tested this, the cake was a bit fluffier and sturdier with an egg in it. Interestingly though, I still preferred the vegan version because it was rich, moist, and more flavorful overall!

In a bowl, whisk together dry ingredients.
In a bowl, whisk together dry ingredients.
Separately, mix wet ingredients until integrated.
Separately, mix wet ingredients until integrated.
Add dry ingredients into wet mixture, folding to integrate.
Add dry ingredients into wet mixture, folding to integrate.

How to Make a Healthy Mug Cake with Banana

  • To start, whisk together flour, baking powder, and salt in a bowl.
  • In a separate bowl, mash banana and mix with maple syrup, almond butter, and nondairy milk.
  • Carefully fold dry into wet mixture until integrated, then stir in any banana bread mix-ins if desired.
  • Grease a large mug (14-16oz) with cooking spray, then add banana mug cake batter.
  • Microwave for 2 minutes and 45 seconds (or more/less, depending on the wattage of your microwave). Test to see if a toothpick comes out clean.
  • Let cake cool for 1 minute in the mug before removing, and rest for 3-5 minutes before enjoying.

Watch how to make this banana mug cake in my Vegan Mug Cakes video!

Grease the inside of a mug with cooking spray. (I think 14-16oz mugs work best.)
Grease the inside of a mug with cooking spray. (I think 14-16oz mugs work best.)
Transfer banana mug cake batter into mug.
Transfer banana mug cake batter into mug.
Cook in microwave based on your machine's wattage. (I cooked this healthy mug cake for 2 minutes 45 seconds in my 900-watt microwave.)
Cook in microwave based on your machine’s wattage. (I cooked this healthy mug cake for 2 minutes 45 seconds in my 900-watt microwave.)

How do you make the best banana mug cake?

  • Check your microwave wattage. Before putting this banana bread mug cake in the microwave, find out the wattage so you can gauge the cook time. Mug cakes are finicky—and even microwaves of the same wattage can cook food differently!
  • Start with a lower cook time and work your way up. The cook time guide below is just a starting point. Cook for less time than what’s listed initially and check the doneness with a toothpick. Then, continue cooking in short intervals until a toothpick comes out clean.
  • If your mug cake is chewy, it’s probably overcooked. When properly cooked, this vegan banana mug cake will be fluffy and moist—not chewy or rubbery. If it’s too dry or chewy, make a note of how long you microwaved it and try again with a shorter cook time.
  • Test and check until you get it right. Mug cakes require some guessing and checking to find the optimal cook time! Once you do, you can keep using that cook time whenever you make this banana mug cake.
When a toothpick comes out clean, your mug cake is done cooking.
When a toothpick comes out clean, your mug cake is done cooking.
Let cake rest in mug for 1 minute before flipping mug over to remove cake.
Let cake rest in mug for 1 minute before flipping mug over to remove cake.
Banana Bread Mug Cake

Mug Cake Cook Time & Microwave Wattage Guide

Use these cook times as a guide, but they are NOT exact. Based on your wattage, start with at least 30 seconds less than what’s listed. Then, test and check to figure out the right time for your microwave. This healthy mug cake cooked for 2 minutes and 45 seconds in my 900-watt microwave, but the exact time will vary—even if you also have a 900-watt microwave.

  • 700-watts: 3 minutes 30 seconds
  • 800-watts: 3 minutes 5 seconds
  • 900-watts: 2 minutes 45 seconds
  • 1000-watts: 2 minutes 30 seconds
  • 1100-watts:  2 minutes 15 seconds
  • 1200-watts: 2 minutes 5 seconds
  • 1300-watts: 1 minute 55 seconds
Gluten Free Banana Mug Cake with Oat Flour

More mug desserts & microwave recipes:

Banana Bread Mug Cake

Banana Bread Mug Cake

A gluten free & vegan banana mug cake made with oat flour & no egg! How to make banana bread in a mug in less than 3 minutes.
5 stars (2 ratings)

Ingredients

  • ¼ cup oat flour, (or gluten free/regular all-purpose flour)
  • ½ tsp baking powder
  • pinch of salt
  • 3 Tbsp mashed banana, (~½ small banana)
  • 1 Tbsp maple syrup, (or granulated sugar, or honey)
  • 1 Tbsp almond butter, (or neutral nut butter)
  • 1 Tbsp nondairy milk

Instructions 

  • In a bowl, whisk together flour, baking powder, and salt.
  • Separately, combine mashed banana, sweetener, almond butter, and milk.
  • Gently fold dry ingredients into wet mixture, until integrated. (Fold in any desired mix-ins, if using.)
  • Spray inside of mug (14-16oz) with cooking spray. Add batter.
  • Microwave 2 minutes 45 seconds, or more/less depending on your microwave wattage. (I tested this recipe in my 900-watt microwave—see cook time guidance below and adjust for your microwave.) Test to see if a toothpick comes out clean.
  • Allow to cool 1 minute in mug. Place a plate on top of mug, then flip and tap mug with a spoon to remove mug cake. Rest 3-5 minutes before cutting and eating.
  • Best enjoyed immediately!

To make mug cake with an egg:

  • Replace 1 Tbsp nut butter + 1 Tbsp nondairy milk with 1 whisked egg.
  • When cooking, microwave for at least 15-20 seconds less as you test to find the right time in your machine.

Notes

Mug Cake Cook Time based on Microwave Wattage

Check your microwave wattage and reference the times listed below—but these times are NOT exact! Start with at least 30 seconds less than the time listed, then continue to cook in short intervals, testing with a toothpick as you go. You will need to experiment to find the right cook time in your microwave.
  • 700-watts: 3 minutes 30 seconds
  • 800-watts: 3 minutes 5 seconds
  • 900-watts: 2 minutes 45 seconds
  • 1000-watts: 2 minutes 30 seconds
  • 1100-watts: 2 minutes 15 seconds
  • 1200-watts: 2 minutes 5 seconds
  • 1300-watts: 1 minute 55 seconds
*If you make this recipe with an egg, it will need to cook for at least 15-20 seconds less.
Serving: 1mug cake, Calories: 312kcal, Carbohydrates: 49g, Protein: 8g, Fat: 10g, Sodium: 426mg, Fiber: 7g, Sugar: 20g
Did you make this recipe?Share a photo and tag us @mindovermunch — we can’t wait to see what you’ve made!