Easy Lemon Cookie Bar Recipe with Lemon Buttercream Frosting
This lemon cookie bar recipe is soft, chewy, and bursting with citrus flavor, topped with a rich and creamy lemon buttercream frosting.
Ingredients
For the Lemon Cookie Bars:
- 1 tbsp lemon zest, finely grated
- ¾ cup granulated sugar
- ½ cup butter, room temperature
- 1 tsp vanilla
- 1 egg
- ½ tsp salt
- ¼ tsp baking powder
- 1 cup all-purpose flour
For the Lemon Buttercream Frosting:
- 6 tbsp butter, room temperature
- 1 ½ cup powdered sugar, sifted
- 1 tbsp fresh lemon juice
- 1 tsp lemon zest, finely grated
- ¼ tsp salt
- 1 tbsp heavy cream, room temperature
Instructions
Make the Bars:
- Preheat oven to 350°F. Grease and line an 8x8 inch pan with parchment paper, leaving an overhang to use as a sling when removing the bars from the pan.
- In a large mixing bowl, add sugar and lemon zest and work the lemon zest into the sugar using you fingers. Next, add the butter and cream the butter and sugar mixture together until light and fluffy.
- Add vanilla, egg, salt, and baking powder and mix until combined.
- Pour in the flour and mix until you have a thick dough.
- Add the dough to the parchment lined pan and press it evenly across the pan using your fingertips. *You may want to chill the dough in the pan for about 20 minutes to make it easier to spread.
- Bake the lemon cookie bars for 20 minutes until they are just golden brown around the edges.
- Place the pan on a wire rack to cook completely before removing the bars from the pan using the sling method.
Make the Buttercream:
- In the bowl of a stand mixer using the paddle attachment, mix butter, powdered sugar, lemon juice, lemon zest, and salt on low until combined.
- Add the heavy cream and whip on medium high until pale and fluffy.
Frost the Cookie Bars:
- Add the frosting to the cookie bar and spread using an offset spatula.
- Place frosted bars in the fridge until the frosting is set. Then cut into squares using a sharpe knife.