Lemon Blueberry Sheet Cake

A moist, tender lemon blueberry sheet cake topped with a zesty cream cheese frosting. Packed with fresh blueberries and bright citrus flavor, this easy dessert is perfect for crowds.

Why This Recipe Works:

• Sour cream adds acidity and fat, which weakens gluten formation to guarantee an incredibly tender, melt-in-your-mouth crumb.
• Tossing the fresh blueberries in a tablespoon of dry ingredients prevents them from sinking to the bottom of the pan.
• Fresh lemon zest is rubbed directly into the sugar, releasing the oil-soluble flavor compounds for a vibrant citrus aroma that baking extracts can never replicate.

I still remember the exact dent in my mother's aluminum 9x13 pan where the corner always baked a little too fast. On hot July afternoons, I would press my thumb into the warm, springy center of her weekend bakes, leaving a tiny, telltale crater before she could even slide the offset spatula across the top. It was always a simple cake, but it felt like the absolute center of the universe.

This sheet cake is that exact feeling.

But let's be honest about blueberry cakes. Most of them are a soggy, purple-streaked disaster because the berries sink straight to the bottom of the pan and burst, turning the surrounding batter into a gummy, underbaked mess. I tested this with three different flour ratios, and the culprit is always gravity combined with excess moisture. When the fruit releases its water during baking, it destroys the delicate protein matrix of the cake crumb.

The fix is incredibly simple.

We use a thick, sour-cream-based batter that physically holds the berries in place while they bake. Trust me on this one, you do not need a stand mixer to get a bakery-level crumb. Just grab a sturdy whisk, work your forearms until they ache for a minute, and watch the batter come together. It is as easy as making a batch of Lemon Coffee Cake on a lazy Sunday morning.

Lemon Blueberry Sheet Cake

• Publisher Storied Skillet
• Cuisine American
• Category Dessert, Cake
• Prep Time 20 mins
• Cook Time 30 mins
• Servings 12
• Calories 380 calories
• Rating 4.8 4967
• Tags lemon blueberry cake, sheet cake, summer dessert, easy cake recipe

Ingredients

• 2 ½ cups (300g) all-purpose flour, divided
• 1 tbsp baking powder
• ½ tsp Diamond Crystal kosher salt
• 1 cup (200g) granulated sugar
• Zest of 2 large lemons
• ½ cup (115g) unsalted butter, melted and cooled slightly
• 3 large eggs, room temperature
• 1 cup (240g) sour cream, room temperature
• 1 tsp pure vanilla extract
• 2 cups (300g) fresh blueberries
• 8 oz (225g) brick cream cheese, softened
• ¼ cup (60g) unsalted butter, softened
• 2 cups (240g) powdered sugar
• 1 tbsp fresh lemon juice
• 1 tsp lemon zest (for frosting)

Directions

1. Preheat your oven to 350°F (175°C). Grease a 9x13-inch metal baking pan with butter or non-stick spray, then line the bottom with parchment paper for easy removal.
2. In a medium bowl, whisk together 2 ¼ cups of the flour, the baking powder, and the Diamond Crystal kosher salt.
3. In a large bowl, combine the granulated sugar and lemon zest. Use your fingertips to rub the zest into the sugar until it is fragrant and damp.
4. Whisk the melted butter, eggs, sour cream, and vanilla extract into the lemon sugar until completely smooth.
5. Fold the dry ingredients into the wet ingredients using a rubber spatula just until combined. Do not overmix, or the cake will become dense.
6. Toss the blueberries with the remaining ¼ cup of flour in a small bowl until coated, then gently fold them into the batter.
7. Spread the batter evenly into the prepared pan. Bake for 28 to 32 minutes, or until a toothpick inserted into the center comes out clean. Let cool completely.
8. Make the frosting by beating the cream cheese and butter together until smooth. Gradually add the powdered sugar, lemon juice, and lemon zest, beating until light and fluffy. Spread over the cooled cake.

Notes

• I highly recommend using Diamond Crystal kosher salt for this recipe. If you only have fine table salt, cut the measurement in half (use ¼ teaspoon instead of ½ teaspoon) to avoid an overly salty cake.
• Sour cream is essential here because its high fat content coats the flour proteins, limiting gluten development. This ensures the cake remains incredibly tender even with the heavy moisture of the blueberries.
• Keep a close eye on the cake starting at the 25-minute mark. Because sheet cakes have a high surface-area-to-volume ratio, they can dry out in a matter of minutes if left in the oven too long.
• This cake actually tastes better on day two. After a night in the fridge, the lemon oils in the frosting meld with the crumb, making it incredibly moist and cohesive.
• If you must use frozen blueberries, do not thaw them first. Thawing will release too much juice and turn your entire cake batter a dull gray-purple color.

Serving Suggestions

This sheet cake is a showstopper on its own, but you can easily dress it up for a backyard gathering or a festive holiday dessert table.

• Serve with a generous scoop of vanilla bean ice cream to balance the bright citrus notes.
• Garnish with extra fresh blueberries and thin lemon wheels for a beautiful presentation.
• Pair it with a refreshing glass of Grated Lemon Lemonade on a hot summer afternoon.
• Slice it into small squares and serve alongside a 4th of July Cake for a patriotic dessert spread.
• Dust the top with a tiny bit of extra lemon zest right before slicing to release fresh aromatic oils.

Storage and Reheating

Store this cake in the fridge.

Because of the fresh cream cheese in the frosting, leaving it on the counter is a recipe for sour disappointment. Wrap the pan tightly in plastic wrap or transfer individual slices to an airtight container. It will keep beautifully for up to five days.

If you prefer to eat it warm, let a slice sit on the counter for twenty minutes before serving. The butter in the cake will soften back up to its perfect, velvety texture.

You can also freeze the unfrosted cake layers. Wrap the cooled cake tightly in a double layer of plastic wrap and aluminum foil, then freeze for up to three months. Thaw overnight in the refrigerator before frosting and serving.

Ingredient Substitutes

If you find yourself missing an ingredient, don't panic. Here are the easiest swaps that won't ruin your bake.

1. Sour Cream: You can substitute full-fat Greek yogurt in a 1:1 ratio. Avoid non-fat varieties, as we need that fat to keep the crumb tender.
2. Blueberries: Fresh blackberries or raspberries work beautifully here. If you want a different citrus profile, try making Lemon Bars instead.
3. Cream Cheese: If you want a lighter topping, swap the cream cheese frosting for a simple glaze made of powdered sugar and lemon juice.
4. All-Purpose Flour: A 1:1 gluten-free baking flour blend can be used, though the texture may be slightly more delicate.

There is something so deeply satisfying about slicing into a sheet cake and seeing those perfect pockets of jammy blue fruit scattered throughout the bright yellow crumb. It is simple, honest baking at its absolute best. I hope this cake brings a little bit of that warm, sunny weekend magic into your kitchen this week.