Oatmeal Mug Cake
The quickest, easiest baked oatmeal you’ll make- this simple oatmeal mug cake is a tender oat cake with delicate banana flavor, melty dark chocolate and peanut butter. It is perfect as a balanced breakfast or a single serving dessert when craving something sweet!
When I was in college I went on a major mug cake kick. They were trendy no doubt, but I made them purely out of necessity. We had a microwave and electric kettle in my dorm room but that’s about it by way of “food preparation” materials. I always had a stash of oats, peanut butter, chocolate and would constantly take apples and bananas from the cafeteria to keep as snacks. So THIS oatmeal mug cake brings back my college days.
Let’s be real, I did NOT generally have time to make it to the cafeteria for breakfast so it was usually oats in the microwave for a quick breakfast as I ran out the door to class. My oat creations were a bit simpler back then but I wanted to bring back that same vibe with this banana oatmeal mug cake.
I’m more of a savory gal for breakfast (helloooo avocado toast) BUT when I have a sweet tooth in the morning, this chocolate oat flour mug cake hits the spot with a cup of coffee. And if you don’t have it for breakfast, this is a yummy, quick dessert. I bet you already have some of these wholesome ingredients in your pantry!
Simple ingredients you’ll need:
Banana: mashed banana provides moisture and sweetness and gives a lovely banana flavor to this mug cake. If you don’t like banana you can use unsweetened applesauce.
Coconut oil: oil or butter in a cake provides moisture and gives it more of a “cake-feel” vs just being baked oatmeal.
Peanut butter: heart-healthy fats and amazing nutty flavor- peanut butter is SO yummy here. But it is not ‘essential’ to the recipe so feel free to leave it out if you prefer!
Maple syrup: maple syrup provides just a little sweetness and elevates the other flavors. You could also use honey, brown sugar, cane sugar or agave nectar.
Ground flaxseed: ground flaxseed is an amazing source of omega-3 fatty acids and fiber and, when combined with warm water, creates an egg-like substance that provides structure to our mug cake.
Vanilla extract: for a little bump of vanilla flavor (easy to leave out if you don’t have it).
Old-fashioned oats: oats are the star of the show in an oatmeal mug cake. I use rolled oats but you could also use minute oats (quick oats).
Oat flour: oat flour is oats that have been ground or pulsed into powder form. You can super easily do this yourself by placing oats in a blender and blending until completely ground.
Protein powder: I love adding about ½ scoop of protein powder to provide balance to this healthy mug cake recipe, but if you don’t have protein powder, don’t sweat it! The recipe will still turn out.
Baking powder: baking powder is the key leavening agent that helps this single-serve cake rise in the microwave.
Salt: salt lifts all the other flavors of chocolate, cinnamon, peanut butter and banana.
Cinnamon: you can hardly have oats without cinnamon right!? Find ground cinnamon in the spice aisle of any regular grocery store. I like to buy it in bulk at Costco for the best price.
Dark chocolate: chocolate chips, chocolate chunks or chopped dark chocolate bar, all will work! I love using a nice quality 70% dark (or higher) chocolate bar.
How to make this easy oatmeal mug cake:
In a large microwave-safe mug (at least 12oz, I used a 16oz mug) mash the banana. Add the remainder of the wet ingredients: coconut oil, peanut butter, syrup, flax ‘egg’ and vanilla extract and whisk until combined.
Stir in the dry ingredients: oats, oat flour, protein powder, baking powder, pinch of salt and cinnamon. If your mixture seems dry you can add one tablespoon milk of choice (almond milk, oat milk, soy milk, etc) I generally do not need to use any additional liquid.
Fold in the chocolate chips or chocolate chunks. I put the chocolate on top and then gently press it into the oatmeal mug cake batter.
Microwave for 60-90 seconds. Keep a close eye on it- mine is usually done in exactly 60 seconds. Serve warm drizzled with more peanut butter, a little honey drizzle and a pinch of flaky sea salt.
It’s a beautiful morning for breakfast.
Expert tips and variation ideas:
- Make sure to use overripe bananas as these are the sweetest and offer the most moisture. This banana mug cake is a great way to use bananas that are almost bad!
- Use wider, taller mugs to avoid it spilling over OR make this recipe into two smaller mug cakes.
- If you added a scoop of vanilla ice cream, I’d tell you that’s a very good idea. OR add 8-10 grams of protein with a big dollop of plain Greek yogurt on top!
- If you don’t like banana, use unsweetened applesauce or canned pumpkin instead. If you do use either of these options you may need to add an extra tablespoon of maple syrup.
- Use almond butter or cashew butter instead of peanut butter, if desired.
- Go wild with your toppings! Fresh berries, toasted coconut, hemp hearts, chia seeds, Greek yogurt, chopped walnuts or pecans, etc.
FAQs
Yep! Add three tablespoons of oats to a high powered blender and blend until completely ground. I use the small attachment for my Vitamix to make a small quantity but you could add several cups of oats to a larger blender to make a bigger quantity.
Use one whole egg instead of the flaxseed/water mixture.
Substitute the banana with ¼ cup unsweetened applesauce.
I’d recommend leaving it out. Your cake will have less protein and be slightly less sweet (if the protein powder is sweetened) so you may want to adjust accordingly like a little drizzle of honey or dollop of Greek yogurt when you serve it!
You can fully prep the batter in the mug and keep it in the fridge for up to 24 hours until you’re ready to pop it in the microwave!
As long as you use certified gluten-free oats than yes, this recipe is gluten-free.
If you love this oatmeal mug cake you’ll love these other oat-inspired healthy breakfasts!
If you try and like this recipe please don’t forget to leave a comment and star rating down below! If you love more lifestyle, behind the scenes and ‘eating in real life’ type of content come find me over on Instagram, @itsaflavorfullife, I love connecting with you all there!
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Oatmeal Mug Cake
- Prep Time: 4 minutes
- Cook Time: 1 minute
- Total Time: 5 minutes
- Yield: 1–2 servings 1x
- Category: Breakfast
- Method: Microwave
- Cuisine: American
- Diet: Vegan
Description
Done in five minutes flat, this easy banana chocolate oatmeal mug cake is a balanced breakfast or healthy, tasty dessert.
Ingredients
- 1/2 very ripe banana, mashed
- 1/2 tablespoon coconut oil, melted
- 1/2 tablespoon peanut butter
- 1 tablespoon pure maple syrup
- 1 tablespoon ground flaxseed whisked with 3 tablespoons warm water
- Splash of vanilla extract
- 3 tablespoons rolled oats
- 3 tablespoons oat flour
- 1/2 scoop vanilla protein powder (optional)
- 1 teaspoon baking powder
- Pinch of salt
- Dash of cinnamon
- 1/2oz dark chocolate chips, chunks or chopped
Instructions
Whisk together the ground flaxseed and warm water in a small bowl, set aside to let thicken. In a large mug (at least 12oz, I used a 16oz mug) mash the banana. Add the remainder of the wet ingredients: coconut oil, peanut butter, syrup, flax ‘egg’ and vanilla extract and whisk until combined.
Stir in the dry ingredients: oats, oat flour, protein powder, baking powder, salt and cinnamon. Fold in the chocolate chips or chocolate chunks. I put the chocolate on top and then gently press it into the batter.
Microwave for 60-90 seconds. Serve warm drizzled with more peanut butter, honey or syrup and a pinch of flaky sea salt.
Notes
This could serve 1 or 2, depending on your appetite and whether it’s more of a snack or a meal, up to you!
If you don’t have oat flour, add three tablespoons of oats to a blender and blend until completely ground. Voila! Oat flour.
You can use one whole egg instead of the flaxseed + water.
See above blog post for step-by-step photos, expert tips and answers to frequently asked questions.
Nutrition
- Serving Size: 1 cake
- Calories: 580
- Sugar: 25.9 g
- Sodium: 117.6 mg
- Fat: 26.4 g
- Carbohydrates: 65.8 g
- Fiber: 10.3 g
- Protein: 20.1 g
- Cholesterol: 5.5 mg
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I rarely leave a review but I needed to this time!!
I happened to have everything this quick recipe required except flaxseed and so I substituted like the note said with an egg and maple syrup which I substituted with brown sugar ….OMG this satisfied my sweet tooth while filling
me up as well…soooooooo goooddddd if ur reading this and are considering making it just make it you won’t regret it!
Yaaassss so happy to hear this Erika! Glad to hear those substitutions worked out great, I know that will be helpful for others 🙂 Glad you loved it and thanks for your review!
I have been looking for a mug cake recipe that is kind of healthy for years and this is the one! Very moist. So good!
Yaaay! Kinda healthy mug cakes fo’ life!🤘🏼