Lemon Blueberry Sheet Cake

Lemon Blueberry Sheet Cake is the kind of dessert I turn to when I want something that feels special but doesn’t demand the time or effort of a layer cake. It’s light, moist, and bursting with tart lemon and sweet blueberries. The simple lemon glaze on top adds just enough zing to keep every bite bright and refreshing. Whether I’m baking for a potluck, a summer BBQ, or just an afternoon treat, this sheet cake never lets me down.

Why You’ll Love This Recipe

I love how effortlessly this cake comes together. There’s no stacking, no frosting layers—just one pan, one beautiful cake. The combination of lemon and blueberry is fresh, fruity, and a little nostalgic. The buttermilk makes it incredibly tender, while the lemon glaze gives it a gorgeous finish. And because it’s all done in a single 9×13 dish, cleanup is a breeze. It’s one of those recipes that feels fancy without being fussy.

Ingredients

(Here’s a tip: Check out the full list of ingredients and measurements in the recipe card below.)

3 cups all-purpose flour
2 teaspoons baking powder
1/2 teaspoon baking soda
1 1/4 teaspoon salt
1 cup butter, softened
1 1/2 cups granulated sugar
Juice and zest of 2 lemons (about 1/4 cup juice)
4 large eggs
1 cup buttermilk
2 teaspoons vanilla extract
1 1/2 cups fresh blueberries, tossed with 1 tablespoon flour

For the glaze:
2 1/2 cups powdered sugar
1/3 cup lemon juice

Directions

Prep the pan and oven: I start by preheating my oven to 350°F (175°C). Then I grease a 9×13 baking dish and line it with parchment paper, letting the edges hang over the long sides to make removing the cake easy later on.

Mix the dry ingredients: In a medium bowl, I whisk together the flour, baking powder, baking soda, and salt. I set this aside while I work on the wet ingredients.

Cream the butter and sugar: Using a stand or hand mixer, I beat the butter and sugar together until light and fluffy. Then I mix in the eggs, vanilla, and buttermilk on low speed until just combined.

Add the lemon and blueberries: I mix in the lemon juice and zest, then fold in the floured blueberries gently with a spatula so they don’t break apart.

Bake the cake: I pour the batter into the prepared pan and smooth the top. I bake it for 40–45 minutes, or until a toothpick comes out with moist crumbs. I let the cake cool completely before glazing.

Make and pour the glaze: I mix the powdered sugar with the lemon juice until smooth. Then I pour it over the cooled cake and let it set until it firms up into a shiny, slightly tangy layer.

Servings and timing

Servings: Makes 16 slices
Preparation time: 20 minutes
Cook time: 45 minutes
Total time: About 1 hour 5 minutes

Variations

When I want to change things up, I sometimes use raspberries or blackberries instead of blueberries—they add a slightly different flavor but work beautifully. If I don’t have buttermilk, I mix 1 tablespoon of lemon juice into 1 cup of regular milk as a substitute. And for a little extra indulgence, I’ve even added a thin layer of cream cheese glaze on top instead of the lemon glaze.

storage/reheating

I store this cake covered at room temperature for up to 2 days, or in the fridge for up to 5. It stays moist and delicious either way. When I refrigerate it, I let it sit at room temp for 15 minutes before serving. It’s not a cake that needs reheating, but if I do want a warm slice, a quick 10–15 seconds in the microwave does the trick.

FAQs

Can I use frozen blueberries?

Yes, I can—just make sure not to thaw them first. I toss them with flour to prevent them from sinking and turning the batter purple.

What can I use instead of buttermilk?

I make a quick substitute by combining 1 tablespoon lemon juice or vinegar with 1 cup of milk. Let it sit for 5–10 minutes and it’s good to go.

Can I make this cake ahead of time?

Absolutely. I often bake it a day ahead and glaze it the day I plan to serve. The flavor actually improves slightly after resting.

How do I prevent the blueberries from sinking?

I always toss them with a little flour before adding them to the batter. This helps them stay suspended throughout the cake.

Do I need to refrigerate the cake after glazing?

Not necessarily. If I’m serving it within a day or two, I leave it covered on the counter. For longer storage, I refrigerate it to keep it fresh.

Conclusion

Lemon Blueberry Sheet Cake is the kind of dessert that fits every occasion—it’s casual enough for a backyard gathering, yet pretty enough for a brunch spread. I love how easy it is to throw together and how perfectly balanced the sweet and tart flavors are. With its moist crumb, juicy berries, and bright glaze, it’s a recipe I come back to again and again.

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