Blueberry-Lemon Sponge Cake in a Mug
Published Sep 17, 2026
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Sometimes you just need a little something sweet.
Not a whole cake. Not two dozen cookies. Not a dessert that leaves you staring at leftovers for the next three days.
Just one warm, delicious treat made especially for you.

Table of Contents
- The Perfect Dessert for One
- Why You’ll Love This Blueberry-Lemon Mug Cake
- Bob’s Red Mill Makes This Gluten-Free Treat Easy
- What You’ll Need
- A Mug Cake That’s Actually Fun to Make
- Fresh Blueberries Make It Special
- Don’t Skip the Lemon Glaze
- A Quick Dessert for When You Just Need a Treat
- Frequently Asked Questions
- Sometimes One Is Exactly Enough
- Blueberry-Lemon Sponge Cake in a Mug Recipe
That’s exactly what this Blueberry-Lemon Sponge Cake in a Mug is all about. It’s a soft, tender little gluten-free cake bursting with fresh blueberries and bright lemon flavor, topped with a simple lemon glaze. And the best part? It goes from pantry to mug to dessert in just a few minutes.
Because sometimes you don’t need to bake for a crowd. Sometimes you just need cake.
The Perfect Dessert for One
There are times when a full-size dessert simply isn’t what you’re looking for. Maybe you have a sweet tooth after dinner. Maybe you’re craving something homemade on a quiet afternoon. Or maybe everyone else in the house wants something completely different.
Whatever the reason, this single-serving mug cake is the answer.
It’s made right in a microwave-safe mug, so there’s no mixing bowl full of dishes and no waiting for the oven to preheat. The cake cooks in just 60–90 seconds, making it one of those recipes you’ll want to keep tucked away for the next time a dessert craving strikes.
And because it serves one, there are no leftovers tempting you from the kitchen counter.
Well, unless you decide to make another one.
Why You’ll Love This Blueberry-Lemon Mug Cake
This little cake may be small, but it has plenty of flavor.
The combination of fresh blueberries and lemon is bright, fresh, and wonderfully summery. Lemon zest goes right into the cake batter, while a simple lemon glaze adds an extra pop of citrus on top.
The blueberries become soft and juicy as the cake cooks, giving you little bursts of berry flavor in every bite.
And then there’s that glaze.
A quick combination of powdered sugar, fresh lemon juice, and lemon zest creates a sweet-tart drizzle that takes this from mug cake to I definitely meant to make something this good.
Bob’s Red Mill Makes This Gluten-Free Treat Easy
This single-serving cake uses Bob’s Red Mill 1-to-1 Baking Flour, making it easy to enjoy a homemade gluten-free dessert without having to pull out a collection of different gluten-free flours.
Bob’s Red Mill 1-to-1 is one of those pantry staples that makes gluten-free baking much less complicated. Just measure it, add it to your mug, and you’re on your way to cake.
And if you’ve noticed that the packaging looks a little different lately, don’t worry! Bob’s Red Mill 1-to-1 Baking Flour has new packaging, but it’s still the same great 1-to-1 flour we’ve all come to rely upon for gluten-free baking.
So whether you’re stocking up for holiday baking, weekend treats, or those random Tuesday-night dessert cravings, you can still count on the same dependable flour.
What You’ll Need

For the Blueberry-Lemon Sponge Cake
- Bob’s Red Mill 1-to-1 Baking Flour
- Granulated sugar
- Baking powder
- A pinch of salt
- Milk
- Unsalted butter, melted
- Pure vanilla extract
- Fresh lemon zest
- Fresh blueberries
The ingredient list is wonderfully simple, with fresh blueberries and lemon zest providing the bright flavor that makes this little cake feel special.
For the Lemon Glaze
- Powdered sugar
- Fresh lemon juice
- Fresh lemon zest
The glaze takes just a few ingredients and adds the perfect sweet-and-tangy finish to the warm cake.
A Mug Cake That’s Actually Fun to Make
There’s something inherently fun about making dessert in a mug.
You mix everything together, gently fold in the blueberries, pop the mug into the microwave, and watch the cake puff up.
And because microwaves vary, you’ll want to start checking the cake at about 60 seconds. It should be puffed and the center should be just set. The recipe cautions against overcooking because that can make the cake rubbery.
That’s really the only tricky part: don’t walk away!
A minute can make a big difference when you’re making a cake this small.
Fresh Blueberries Make It Special
You could certainly make a mug cake without fruit, but fresh blueberries make this one extra delicious. And if all you have are frozen blueberries, no worries. They work just fine, you don’t even need to defrost!
The berries are gently folded into the batter so they stay intact, then soften as the cake cooks. You end up with juicy little pockets of blueberry throughout the tender lemon cake.
For an especially pretty finish, save a few fresh blueberries to scatter over the top along with a little extra lemon zest.
Don’t Skip the Lemon Glaze
The lemon glaze is quick enough that there’s really no reason to skip it.
While the cake is cooking, whisk together powdered sugar, fresh lemon juice, and lemon zest until smooth. If it seems too thick, add a tiny bit more lemon juice.
Then let the cake cool for a minute or two before drizzling the glaze over the top.
That little drizzle adds just the right amount of sweetness and makes the whole thing look much more impressive than the amount of effort would suggest.
A Quick Dessert for When You Just Need a Treat
This is the recipe to remember when the words “I want something sweet” pop into your head.
It doesn’t require a special occasion. You don’t need to wait for company. And you don’t need to commit to baking an entire dessert.
You just need a mug or ramekin.
The cake is gluten-free, egg-free, nut-free, soy-free, and vegetarian, so it’s also a handy little recipe to have when you need a dessert that fits several dietary needs.
And because it makes just one serving, it’s perfect for those moments when you want something homemade without making a big batch.
Frequently Asked Questions
Yes! This recipe is gluten-free and uses Bob’s Red Mill 1-to-1 Baking Flour. It’s also egg-free, nut-free, soy-free, and vegetarian.
Just one! This recipe is designed as a single-serving dessert, making it perfect when you’re craving something sweet but don’t want to make an entire cake.
Yes! No need to even defrost them.
The cake cooks in the microwave for approximately 60–90 seconds. Start checking it at 60 seconds because microwave strength can vary.
The cake should be puffed and the center should be just set. Be careful not to overcook it, as overcooking can make the cake rubbery.
You can, but the lemon glaze is such an easy way to add extra lemon flavor and sweetness that it’s worth making. It takes just powdered sugar, fresh lemon juice, and lemon zest.
The recipe calls for Bob’s Red Mill 1-to-1 Baking Flour. And don’t be concerned if you notice new packaging on the shelf, the packaging has changed, but it’s still the same great 1-to-1 flour we’ve come to rely upon for gluten-free baking.
This recipe is designed to be prepared and served warm, so it’s best enjoyed shortly after cooking. The recipe recommends letting it cool for just 1–2 minutes before adding the glaze and serving.

Sometimes One Is Exactly Enough
There’s a lot to love about a dessert that knows when to keep things simple.
This Blueberry-Lemon Sponge Cake in a Mug gives you everything you want from a homemade cake—tender crumb, juicy blueberries, bright lemon flavor, and a sweet glaze—but in a perfectly portioned dessert for one.
It’s quick enough for a last-minute craving, easy enough for a lazy afternoon, and delicious enough that you won’t miss having a whole cake sitting on the counter.
So the next time you think, “I just need a little treat,” grab a mug, reach for your Bob’s Red Mill 1-to-1 Baking Flour, and make yourself a cake.
Because sometimes one little cake is exactly what you need.

Blueberry-Lemon Sponge Cake in a Mug
Ingredients
- 3 tablespoons Bob’s Red Mill 1-to-1 Baking Flour
- 2 tablespoons granulated sugar
- ⅛ teaspoon baking powder
- Pinch of salt
- 2 tablespoons milk
- 1 tablespoon unsalted butter, melted
- ½ teaspoon pure vanilla extract
- ½ teaspoon finely grated lemon zest
- 2 tablespoons fresh blueberries
- For the Lemon Glaze
- 2 tablespoons powdered sugar
- ½ teaspoon fresh lemon juice
- ¼ teaspoon finely grated lemon zest
Instructions
- Lightly grease a microwave-safe 10- to 12-ounce mug with butter or nonstick cooking spray.
- In the mug, whisk together the Bob’s Red Mill 1-to-1 Baking Flour, sugar, baking powder, and salt. Add the milk, melted butter, vanilla, and lemon zest. Stir just until combined and no dry streaks remain.
- Gently fold in the blueberries, being careful not to crush them.
- Microwave on high for 60 to 90 seconds, or until the cake is puffed and the center is just set. Start checking at 60 seconds because microwave strength varies. Avoid overcooking, which can make the cake rubbery.
- While the cake cooks, whisk together the powdered sugar, lemon juice, and lemon zest in a small bowl until smooth. If the glaze seems too thick, add a drop or two more lemon juice.
- Let the cake cool for 1 to 2 minutes, then drizzle with the lemon glaze. Garnish with a few fresh blueberries and a little additional lemon zest, if desired. Serve warm.
Nutrition
Nutrition information is automatically calculated, so should only be used as an approximation.













