This Lemon Mug Cake is super easy and full of fresh, citrusy flavor. It’s a quick mug cake recipe you can make in the microwave, perfect when you want a cozy single-serve dessert fast! Soft, sweet, and lemony, this microwave lemon cake totally hits the spot. If you’re into quick treats, don’t miss my collection of 15-Minute Easy Desserts for plenty of sweet inspiration when you are short on time. If you love mug cakes, be sure to try my Brownie in a Mug next!
Ingredients & Substitutions
- Butter: Melting the butter (I prefer unsalted butter) helps everything mix together easily and gives the cake a soft, moist texture. Salted butter works, too, but you may want to leave out the salt in the recipe.
- Egg: You will only use the yolk of one large egg, making the cake rich and tender without adding too much moisture. Using the entire egg would make this small mug cake rubbery. But, don’t throw out the egg white; save it for another recipe like almond paste or fried ice cream.
- Lemon Juice: If possible, use freshly squeezed lemon juice. It brightens up both the cake and the glaze with that fresh, tangy zing.
- Lemon Zest: The lemon zest is optional, but I highly encourage adding it. After all, this is a lemon dessert, so I want the lemon flavor to shine through!
- Lemon Glaze: The easy lemon glaze is a simple way to add a little extra sweetness and zing. Just mix confectioners’ sugar (powdered sugar) with some lemon juice, and you’ve got a tasty drizzle that makes the mug cake even better. Totally worth it!
Can I Use Bottled Lemon Juice Instead Of Fresh In Lemon Mug Cake?
Absolutely! You can use bottled lemon juice instead of fresh in your lemon mug cake. Just keep in mind that fresh lemon juice gives a brighter, more vibrant flavor, while bottled juice might be a bit milder or less fresh-tasting. But, bottled juice still works well in a pinch.
Why You’ll Love This Lemon Mug Cake
I am sure you can already figure out why you will love this lemon mug cake! It’s an easy lemon dessert you can make in just minutes, with fresh, bright lemon flavor and a soft, moist texture. Plus, it’s a single-serve microwave lemon cake, meaning no oven, no mess, and just the right amount to satisfy your sweet tooth fast.
Lemon Mug Cake Troubleshooting: How to Fix Dry, Dense, or Undercooked Microwave Lemon Cakes
- Dry or rubbery cake: Microwave for less time. Start with 60 seconds, then add 10-second increments as needed. Overcooking causes dryness.
- Dense or heavy texture: Measure flour carefully and don’t overmix. Use only the egg yolk for a tender cake.
- Cake won’t rise: Make sure your baking powder is fresh and don’t skip it; it helps the cake fluff up.
- Weak lemon flavor: Use freshly squeezed lemon juice and add lemon zest for extra zing. Bottled lemon juice works, but is less vibrant.
- Glaze too thick or runny: Adjust the amount of lemon juice in the confectioners’ sugar until you get a smooth, pourable glaze.
- Cake sticks to the mug: Spray the mug well with nonstick spray or grease it lightly before adding batter.
- Cake overflows in the microwave: Use an 8-ounce (or larger) mug to give the batter room to rise, and avoid filling the mug more than halfway. Microwaves vary, so adjust cooking time if needed to prevent spilling.
Can I Double This Lemon Mug Cake Recipe?
Yes, you can double this lemon mug cake recipe. Use a larger (12-ounce) mug and increase the microwave time to about 90 seconds, adding 15-second bursts as needed. But if you’re making multiple cakes, it’s best to microwave them one at a time for even cooking and to avoid overflow.
How To Store Lemon Mug Cake
Lemon mug cake is best enjoyed fresh, but if you have leftovers, let it cool completely and cover the mug tightly with plastic wrap or transfer the cake to an airtight container. Store in the refrigerator for up to 2 days. Reheat it in the microwave for about 10–15 seconds before serving.
Lemon Mug Cake
Ingredients
- 2 tablespoons unsalted butter, melted
- 2 tablespoons granulated sugar
- 1 large egg yolk
- 1 tablespoon freshly squeezed lemon juice
- ½ teaspoon lemon zest, optional, but recommended
- 2 tablespoons whole milk
- ½ teaspoon pure vanilla extract
- ¼ cup all-purpose flour
- ¼ teaspoon baking powder
- 1 pinch kosher salt
Lemon Glaze
- 2 tablespoons confectioners’ sugar
- ½ to 1 teaspoon freshly squeezed lemon juice
Instructions
- Lightly spray an 8-ounce microwave-safe mug with nonstick cooking spray and set aside.
- In a small mixing bowl, whisk together the melted butter and sugar until smooth.
- Add the egg yolk, lemon juice, lemon zest (if using), milk, and vanilla. Whisk until fully combined and smooth.
- Stir in the flour, baking powder, and salt just until no dry streaks remain. Do not overmix.
- Pour the batter into the prepared mug.
- Microwave on high for 60 to 90 seconds, or until the top is just set and springs back lightly when touched. Avoid overcooking; the cake will continue to firm up as it cools.
- While the cake cools slightly, make the glaze. In a small bowl, stir together the confectioners’ sugar and lemon juice until smooth and pourable.
- Drizzle the glaze over the warm mug cake. Serve immediately.
Did you make this recipe?
Thank you for making my recipe! You took pictures, right? Well go ahead and post them on Instagram! Be sure to mention me @iambaker and use the hashtag #YouAreBaker.
What the Test Kitchen had to say about this recipe:
Autumn
This is super lemony and so soft! I love that it takes only a few minutes to make!
Elizabeth
I am not usually a fan of lemon desserts, but this is great! I love all of our mug cake ideas lately!
Stephanie
I am surprised how good this turned out. If you like lemon desserts, you will love this.
Bella
This is light, moist, and so lemony! I like it, especially with the glaze.
Can it be eaten cool? Or only warm?
You can absolutely enjoy it cool. 🙂