Description
A one-bowl lemon blueberry sheet cake that stays moist for days thanks to sour cream and fresh lemon juice. Topped with a 3-ingredient lemon glaze that sets in 15 minutes. Bakes in a single 9×13 pan and feeds 20 — no stacking, no frosting skills needed.
Ingredients
LEMON BLUEBERRY SHEET CAKE
3 cups (360g) all-purpose flour
2 1/2 teaspoons baking powder
1/2 teaspoon salt
1 cup (230g) unsalted butter, softened to room temperature
2 cups (400g) granulated sugar
4 large eggs, room temperature
1 cup (240g) full-fat sour cream
1/2 cup (120ml) fresh lemon juice (about 3 lemons)
2 tablespoons lemon zest
1 teaspoon pure vanilla extract
2 cups (290g) fresh blueberries
2 tablespoons all-purpose flour (for coating blueberries)
LEMON GLAZE
2 cups (240g) powdered sugar
3–4 tablespoons fresh lemon juice
1 teaspoon lemon zest
Instructions
1. Preheat oven to 350°F. Grease a 9×13 pan with butter or baking spray and line the bottom with parchment paper. Set aside.
2. In a medium bowl, whisk the flour, baking powder, and salt together. Set aside.
3. Beat the softened butter and sugar together on medium-high speed for 3–4 minutes until the mixture turns very light in color and looks fluffy.
4. Add the eggs one at a time, mixing well after each one. Add the sour cream, lemon juice, lemon zest, and vanilla extract; mix until the batter looks smooth and uniform.
5. Add the flour mixture to the wet ingredients and fold with a rubber spatula until just combined — stop as soon as no dry streaks remain. Do not beat.
6. Toss the blueberries with the 2 tablespoons of flour in a small bowl until coated. Fold gently into the batter. Spread into the prepared pan and smooth the top with a spatula.
7. Bake for 35–40 minutes until a toothpick inserted in the center comes out clean or with a few moist crumbs. Cool in the pan on a wire rack for at least 20 minutes before glazing.
8. Whisk powdered sugar, lemon juice, and lemon zest together until smooth. Start with 3 tablespoons of lemon juice; add more a teaspoon at a time until the glaze drips slowly from a spoon — it should flow, not pour. Drizzle over the fully cooled cake and let it set for 15 minutes before slicing.
Notes
Coat the blueberries in flour right before adding them — this step reduces sinking and is not optional.
Fold the flour in gently with a spatula and stop the moment no dry streaks remain. Overmixing activates too much gluten and makes the cake dense instead of tender.
Glaze only a fully cooled cake — glaze on a warm cake soaks straight in and disappears from the surface. Wait a full 30 minutes after the cake comes out of the oven.
For best results, measure flour by spooning into the measuring cup and leveling off — do not scoop directly from the bag. Or use a kitchen scale.
Store covered at room temperature up to 2 days or refrigerated up to 5 days. Pull refrigerated cake out 30 minutes before serving.
Freeze unglazed cake (wrapped tightly in plastic wrap + foil) up to 2 months. Thaw at room temperature; glaze after thawing.
- Prep Time: 20 minutes
- Cook Time: 40 minutes
- Category: Dessert
- Method: Bake
- Cuisine: American