2-Minute Oatmeal Mug Cake

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I often choose healthier options for breakfast, but sometimes I just want cake. This oatmeal mug cake is the PERFECT way to satisfy that sweettooth, while also adding in fiber and wholesome ingredients.

My favorite part? Takes minutes to make in the microwave. Once that beep goes off, you’ll be digging your fork in the most tender, fluffiest, oatmeal mug cake that’s perfectly vegan, gluten-free, and healthy.

It also only requires just 6 pantry staples: oats, vegan milk, maple syrup, peanut butter, baking powder, and chocolate chips (optional).

Let’s not waste any time! Grab your favorite mug and let's get microwaving!

Why You’ll Love This

Budget-Friendly: This recipe uses simple, affordable ingredients you likely already have.
Protein-Packed: Thanks to the oats and peanut butter, you’ll get a good amount of protein to keep you full.
Versatile: Perfect for breakfast, dessert, or even a snack. Top it with whatever you want (because that’s the fun part about being an adult) and enjoy!

What is an Oatmeal Mug Cake?

Cooked oatmeal mug cake topped with sliced almonds and maple syrup.

Oatmeal mug cake is a quick, single-serving dessert made right in a mug! No need to crank on the oven. It’s basically a cozy mix of oats, milk, a little sweetener, and baking powder that gets microwaved for about a minute.

The result is a soft, cake-like treat that tastes like a cross between baked oatmeal and a fluffy muffin. It’s perfect for when you want something warm, sweet, and ready in minutes.

Got Peanut Allergies?

No problem! If peanuts are off the table, you can easily swap peanut butter for sunflower seed butter (sunbutter) in this oat mug cake recipe.

It has a similar creamy texture and rich, nutty flavor, without any peanuts involved. Plus, sunbutter adds a boost of healthy fats and a subtle roasted taste that pairs perfectly with oats and a drizzle of maple syrup.

I find that sunbutter has a softer, liquid texture than peanut butter, when stored at room temperature. Because of this, there is no need to melt it before adding it to the rest of your wet ingredients.

Ingredients & Substitutions

Ingredients: oat flour, maple syrup, baking powder, oat milk, and peanut butter.

Vegan Milk: Use whatever milk you prefer! Almond, oat, or even soy milk will work well to keep this plant-based.
Maple Syrup: Maple syrup provides just the right touch of sweetness. You could also swap this with agave or even a sugar-free syrup.
Peanut Butter: Peanut butter adds richness and protein to the cake. If you’re allergic, feel free to use almond butter, sunflower seed butter, or any nut/seed butter of choice.
Oat Flour: Oat flour gives this cake a soft, tender, hearty texture. You can also use oat bran, but keep in mind the oat cake will be denser.
Baking Powder: This gives the cake a nice lift, making it fluffy and light. Be sure to measure this accurately for the best result.

Step-by-Step Recipe

Step collage to recipe: mix wet ingredients, fold in dry ingredients, top with chocolate chips and sliced almonds, microwave result.

Mix Wet Ingredients: In a microwave-safe mug, combine vegan milk, maple syrup, and peanut butter. Stir until the peanut butter is completely blended in.
Mix Wet Ingredients: In a microwave-safe mug, combine vegan milk, maple syrup, and peanut butter. Stir until the peanut butter is completely blended in.
Microwave & Enjoy: Microwave on high for 1½ to 2 minutes, or until the cake rises and looks firm. Let it cool for a minute before enjoying straight from the mug.

Tips for the Best Oatmeal Cake

Oat milk with mixed with a dollop of peanut butter. Whisk in photo.

Don’t overmix: Once your dry ingredients hit the wet ingredients, gently mix them until just combined. Overmixing will make the cake dense.
Test for doneness: Stick a toothpick in the middle. If it comes out clean, you're good to go!
Cool before enjoying: It might be tempting, but let the cake cool down slightly before enjoying. You'll just need a couple of minutes.
Add mix-ins: Want to jazz it up? Add some cinnamon, chocolate chips, or dried fruit to the batter before baking for a flavor boost.

What to Serve With Oatmeal Cake

If you’re okay with nuts, I highly recommend topping this oat mug cake with sliced almonds, hemp seeds, or crushed walnuts for crunch and texture.

You can also pair it with a side of fresh berries, or a dollop of coconut yogurt. You could even serve it alongside a savory dish, like scrambled tofu or breakfast potatoes, for a more balanced meal.

Mushroom bacon and tempeh bacon are my personal favorites.

Looking for more oat-based breakfast ideas? Check out these oat bran pancakes or some sweet oatmeal cookies for more plant-based breakfast inspiration.

How to Store Oatmeal Cake

The mug cake is best enjoyed fresh. But honestly, it’s so quick to make, you’ll want to whip up a fresh one every time!

You can keep the cake at room temperature in an airtight container for up to 2 days.

To refrigerate the oat cake for longer storage, refrigerate the cake for up to a week. It’ll stay moist and fresh. Just make sure to wrap it tightly or place it in a sealed container.

More Recipes with Oats

Did you try out this Vegan Oatmeal Cake?

Please leave a comment below, share it, rate it, or tag a picture @plantbasedandbroke on Instagram and hashtag it #plantbasedandbroke. Show off that creation with us!

Can I make this gluten-free?

This recipe is already made gluten-free!

Can I use another sweetener?

You can swap out maple syrup for agave, coconut sugar, or a sugar-free alternative.

How do I make this cake fluffier?

Ensure your baking powder is fresh and don’t overmix the batter. Gently fold the ingredients for a lighter cake.

What can I add to this cake for extra flavor?

Try adding cinnamon, vanilla extract, or even chopped nuts for a more textured and flavorful cake.

Are mug cakes with oats healthy?

Yes, oatmeal cakes are healthy as they're made with nutrient-dense ingredients like oats, peanut butter, and plant-based milk, offering fiber, protein, and healthy fats. Plus, they're naturally sweetened with maple syrup for a balanced treat.