Thick and easy, these moist Lemon Sheet Cake bars are bursting with citrus flavor. Topped with a luscious lemon buttercream frosting, you’ll LOVE this recipe!
For an extra burst of lemon flavor, add lemon zest to the frosting!
This lemon cake bar was originally published in January 2020. The recipe notes were updated in April 2025.
Aimee’s Recipe Notes
Taste & Texture: Moist, tender cake with tangy lemon flavor, topped with creamy lemon buttercream frosting.
Storage:
- Store in an airtight container at room temperature for up to 3 days.
- For longer storage, refrigerate for up to a week.
Freezing: Wrap individual bars in plastic wrap and place in a freezer-safe bag. Freeze for up to 1 month. Thaw at room temperature before serving.
Unlike these Gooey Lemon Cake Bars that start with a cake mix, today’s recipe is from scratch, but so easy!
How to Make Lemon Cake Bars
Prepare the Batter: Cream softened butter and sugar until light and fluffy. Mix in eggs, vanilla extract, sour cream, lemon juice, and zest. Gradually add dry ingredients, mixing until just combined.
Bake: Spread the batter evenly in a lined 13×9-inch baking dish. Bake at 350°F for 18-20 minutes until a toothpick inserted in the center comes out clean.
Frost: Once cooled, spread lemon buttercream frosting over the bars.
Serve: Slice into squares and enjoy.
Storing Lemon Cake Bars
Store these lemon cake bars in an airtight container at room temperature.
You can refrigerate these bars if you prefer them chilled (I enjoy them both ways)!
Freezing Lemon Cake Bars
What I love about these cake bars is they freeze beautifully.
You can freeze them with or without the frosting! Just know that the texture will change slightly when frozen with frosting on top.
To freeze, wrap cake bars in plastic wrap then a layer of foil (or slide into a freezer safe ziploc bag or airtight container). Freeze for up to 30 days.
Thaw lemon cake bars overnight in refrigerator or at room temperature. ENJOY.
Tips for Lemon Bars
- Start with softened butter.
- Do not over mix batter, use a wooden spoon to incorporate dry ingredients.
- Use fresh squeezed lemon (not bottled lemon concentrate)
- Cool completely before adding the frosting!
More Lemon Desserts
- Lover of lemon? Try Lemon Cheesecake Bars or this Coconut Lemon Cake to quench that sweet lemon tooth!
- The BEST Lemon Bars recipe is here! Look no further for zesty dreamy treats!
- Start your day off right with this Lemon Biscotti recipe! Try this Lemon Bundt cake too, your children will love it!
- If you love lemon desserts, be sure to try my classic lemon cake recipe. Or give this delicious lemon meringue pie a try soon.
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Lemon Sheet Cake Bars Recipe
Ingredients
For the cake
- 1 cup unsalted butter softened
- 1 cup granulated sugar
- 1 large egg
- 1 teaspoon vanilla extract
- 1 lemon juiced and zested
- ½ cup sour cream
- 2 ⅔ cup all-purpose flour
- 1 teaspoon baking powder
- ½ teaspoon baking soda
- ½ teaspoon kosher salt
For the frosting
- ½ cup unsalted butter softened
- 2 cups powdered sugar
- 1 lemon zested and juiced
- 1 Tablespoon heavy whipping cream
Instructions
- Preheat oven to 350 degrees F. Line a 13×9-inch baking dish with parchment paper or spray with non-stick baking spray (or use my homemade cake release).
- In a large mixing bowl, beat softened butter with sugar until creamy. Add in eggs, vanilla, sour cream, and lemon juice, scraping down the sides of the bowl as needed.
- Using a wooden spoon (so you do not over mix), add in flour, lemon zest, baking powder, baking soda, and kosher salt.
- Spread batter in the prepared baking dish. Bake for 18-20 minutes, remove and cool on wire rack.
- For the frosting, beat softened butter with powdered sugar, lemon juice, lemon zest, and heavy cream. Beat until light and fluffy, for about 3-5 minutes, scraping down the sides of the mixing bowl as needed.
- Spread frosting over cooled cake bars. Slice and enjoy.
Notes
- Start with softened butter.
- Do not over mix batter, use a wooden spoon to incorporate dry ingredients.
- Use fresh squeezed lemon (not bottled lemon concentrate)
- Cool completely before adding the frosting!
Nutrition
Easy Cake Recipes
Thick and easy, these moist Lemon Cake Bars are bursting with citrus flavor. Topped with a luscious lemon buttercream frosting, you’ll LOVE this recipe!
do you need to use sour cream?
This looks so yummy! My son’s birthday is coming up very soon and he asked for something lemon. I think this will work. 🙂