Save I was studying late at night during finals week when the craving hit hard. Something sweet, something fast, something that didn't require washing a single bowl if I could avoid it. I mixed up the first attempt in a chipped mug I'd stolen from the dining hall freshman year, skeptical that anything could actually cook in the microwave. Two minutes later I was sitting on the kitchen floor, spoon in hand, wondering why I'd ever bothered with preheating an oven for a dessert this satisfying.
My roommate caught me making these at 11 PM one Tuesday and looked at me like I'd revealed a state secret. Now we both keep a stash of mini chocolate chips on top of the fridge specifically for mug cake emergencies. Theres something genuinely joyful about having warm cake ready faster than you could decide what to order on a delivery app.
Ingredients
- Creamy peanut butter: I prefer the regular stuff over natural for this one because it melts into the batter more smoothly, but use whatever you have on hand
- Unsalted butter: Melt it in the microwave for about 15 seconds before you start mixing
- Large egg: Room temperature eggs incorporate better into the batter, but I've used cold eggs in a rush and it still works
- Milk: Any milk works here, dairy or not, I've even used water when I was completely out of everything else
- Vanilla extract: Don't skip this, it's what makes it taste like real dessert instead of just peanut butter mush
- All purpose flour: Spoon and level it instead of scooping directly, packing down the flour makes the cake dense
- Granulated sugar: You can reduce this to 1 tablespoon if you prefer it less sweet, especially if using a sweeter peanut butter
- Baking powder: Make sure it's fresh, old baking powder won't give you that nice rise
- Salt: Just a tiny pinch, it cuts through the sweetness and makes the peanut flavor pop
Instructions
- Melt and mix the base:
- Combine the peanut butter and melted butter in your mug, stirring until they form a smooth glossy mixture
- Add the wet ingredients:
- Crack in the egg, pour in the milk and vanilla, then whisk everything with a fork until you can't see any streaks of egg white
- Incorporate the dry ingredients:
- Dump in the flour, sugar, baking powder, and salt all at once, then stir just until you don't see dry powder anymore
- Microwave to perfection:
- Cook on high power for 60 to 75 seconds, watching through the door as it dramatically rises and sets
- Let it rest:
- Walk away for at least one minute, I know this is the hardest part but it finishes cooking and becomes easier to eat
Save My sister visited last month and I made her one after she had a terrible day at work. She took one bite and actually teared up a little, not from the emotional speech I'd prepared but from the fact that warm peanut butter cake at 11 PM is just pure comfort in a mug.
Choosing the Right Mug
I learned this the hard way when my first attempt overflowed all over the microwave turntable. You need at least a 12 ounce mug, basically anything that looks slightly too big for a single serving of coffee. The cake expands significantly while cooking, and you don't want to be scraping batter off the ceiling of your microwave at midnight.
Topping Ideas
Sometimes I go all out and sometimes I eat it plain, both ways are valid. A pat of butter melting into the warm top is practically luxurious, while a handful of chocolate chips pressed into the surface right after microwaving creates this gooey situation that's frankly excellent.
Make It Your Own
I've made enough of these to know that the formula is surprisingly forgiving. Swap in almond butter if that's your preference or throw in a handful of chopped peanuts for texture.
- Try adding a tablespoon of cocoa powder to the dry ingredients for a chocolate peanut butter version
- Mix in some mini chocolate chips before microwaving, they'll melt into pockets of gooey goodness
- A drizzle of honey or maple syrup on top right before serving feels unnecessarily fancy
Save This is the recipe I turn to when I need comfort immediately, no shopping required, no timer to monitor, just me and a mug and two minutes of patience.
Common Questions
- → Can I use a different type of milk?
Yes, you can substitute almond, oat, or any non-dairy milk to make it dairy-free or suit your taste.
- → How long should I microwave the cake?
Microwave on high for 60 to 75 seconds until the cake is risen and set in the center to avoid overcooking.
- → What can I use to enhance the flavor?
Add toppings like chocolate chips, a drizzle of honey, or a scoop of ice cream for extra richness and texture.
- → Is it possible to make this gluten-free?
Yes, replace the all-purpose flour with a gluten-free flour blend using a 1:1 substitution.
- → What utensils are needed to prepare this cake?
A microwave-safe mug and a fork or small whisk are necessary to mix the batter and cook the cake.