Peanut Butter Mug Cake

I’ve been there. It’s 10 PM on a Tuesday. You’re craving something sweet, but the thought of preheating the oven and washing a dozen pans feels like a chore. I once tried to bake a whole batch of cookies just for a single craving, and I ended up with a mountain of dishes and a stomachache.

That’s why I love this Peanut Butter Mug Cake. It’s the perfect “I need dessert right now” fix. It feels like a warm hug in a cup.

Mug cakes got popular because not everyone has a full kitchen. Whether you’re in a dorm or just don’t want to heat up the house, they are a total lifesaver. Most people look for a 3-ingredient version. The problem? Those usually end up tasting like a rubber ball.

This recipe is what I call the Gourmet Upgrade. By adding a little oil and an egg yolk, you get a rich, soft cake that actually tastes like a real dessert. It’s salty, sweet, and reminds me of those classic “Elvis” flavors.

The Game Plan

If you want an Easy Peanut Butter Mug Cake, this is it. It takes about 2 minutes to prep and a little over a minute to cook.

The good news? This is a “Level 1” recipe. It’s great for beginners or kids. You just need a standard 10–12 oz mug. Anything smaller might cause a “cake-cano” overflow in your microwave. Trust me, cleaning exploded cake off a microwave turntable is not how you want to spend your night.

Equipment	What to use instead
12 oz Ceramic Mug	A small microwave-safe bowl
Mini Whisk	A regular dinner fork
Measuring Spoons	A standard soup spoon (about 1 tbsp)

What You’ll Need

The star of the show is the peanut butter. I usually grab a jar of Jif or Skippy because they are consistent. If you use the natural stuff that you have to stir, make sure it’s mixed really well. If you get the dry bits from the bottom of the jar, your cake will be a desert.

Here is your shopping list:

• Peanut Butter: 2 tablespoons.
• Oil: 1.5 tablespoons. This keeps it moist.
• Sugar: 2 tablespoons.
• Egg Yolk: 1 large. This is the secret for a custard-like texture.
• All-purpose Flour: 2 tablespoons.
• Baking Powder: 1/4 teaspoon.
• Milk: 1 tablespoon (plus a splash if needed).
• Chocolate Chips: (Optional, but highly recommended).

Quick Tip: Try to use a room-temperature egg and milk. If they are freezing cold, they can make the peanut butter seize up. It’s like trying to stir cement.

Let’s Cook Together!

Step 1: The Liquid Base

Grab your mug. Toss in the oil, peanut butter, sugar, and egg yolk. Whisk them until they look like a smooth, glossy paste. You want that sugar to start dissolving. If your peanut butter is too stiff to stir, pop the mug in the microwave for 10 seconds to soften it up.

Step 2: Add the Structure

Slowly whisk in the flour and baking powder. Don’t dump it all in at once or you’ll get flour clumps. Once it’s thick, stir in the milk and chocolate chips. It should look like thick Greek yogurt. If it looks like bread dough, add a tiny bit more milk.

Step 3: The Magic Moment

Stick it in the microwave. I usually go for 1 minute and 30 seconds, but every microwave is a different beast. Watch it through the glass! It will rise high and then settle back down.

The goal? Take it out when it’s 95% done. If the top looks set and springs back when you poke it, it’s ready. Let it rest for 1 or 2 minutes. This “Resting Phase” lets the center finish cooking so you don’t end up with a hockey puck.

Mix it Up

You can totally change this recipe to fit your mood. Because let’s be honest, sometimes you want to get creative.

• The Elvis: Mash up half a banana and mix it in.¹
• The Mocha: Add 1/2 teaspoon of espresso powder to the wet ingredients.
• The Festive Version: Use white chocolate chips and a pinch of cinnamon.
• Vegan/GF: Use a 1-to-1 gluten-free flour. Swap the egg for a tablespoon of applesauce and use almond milk.

Serving it Up

You can eat it straight from the mug, or go “fancy cafe” style. A scoop of vanilla ice cream on top is heavenly because of the hot-cold contrast.

Mug cakes are best when they are fresh. If you can’t finish it, cover it with plastic wrap. It stays okay at room temperature for a few hours, but I wouldn’t freeze it. If it gets cold, just zap it for 10 seconds to bring back the gooey center.

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