In this next installment of dishes/desserts that I’ve always thought were harder to make than they actually are: lemon squares…or lemon bars or whatever you end up calling them. These are traditionally made with a shortbread crust and a lemon-flavored custard filling dusted with powdered filling to finish. And my recipe keeps things very simple and close to the traditional recipe with some slight adjustments (totally optional personal preferences) to give each bite a bit more lemon taste and the crust a bit more depth of flavor.
Your grocery list
Produce
- Lemons (needed for the juice and zest, which is optional)
Dairy
- Large eggs
- Unsalted butter (cold)
Baking and pantry items
- White sugar
- All-purpose flour
- Baking powder
- Powdered (confectioner’s sugar), for dusting at the end
- Salt
Equipment/tools you’ll need
- Cooking spray
- 9×13″ cake or roasting pan
- Food processor (to easily combine shortbread crust)
- Stand or electric hand mixer
- Sift (for dusting sugar, optional)
- Microplane for grating lemon zest
Step-by-step instructions for making lemon squares
1) Make shortbread crust and bake
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Preheat the oven to 350 degrees F (175 degrees C). Coat a 9×13-inch baking dish with cooking spray.
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Combine 2 cups of all-purpose flour, unsalted butter, and 1/2 cup powdered sugar in the bowl of a food processor; pulse until mixture resembles coarse crumbs. Press the mixture into the prepared baking dish. TIP: Use the bottom of a measuring cup to press evenly.
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Bake in the preheated oven until crust edges are golden brown, 18 to 22 minutes. Cool to room temperature.
2) Make custard filling
- Beat white sugar, eggs, 1/4 cup of flour, lemon juice, baking powder, and lemon zest together in a bowl using an electric mixer until light and fluffy; pour onto the cooled crust.
- Each lemon should result in about 3-4 tablespoons of juice so 1-2 lemons should be enough for the 1/4 cup of lemon juice needed in the custard.
3) Bake custard, let it cool, then coat with sugar
- Bake in the oven until custard is set, 25 to 28 minutes. Completely cool lemon squares; dust top with confectioners’ sugar and serve.
- How to know when the lemon squares are done: You know when your lemon squares are done when you gently shake the pan and the filling is set and no longer jiggles. Be sure to let the squares completely cool before cutting. They need time to set up, so don’t rush this step. I like to let them cool at room temperature for about an hour then refrigerate for another 1-2 hours before cutting for the cleanest cuts.
Tips for making great lemon squares
- Use real lemon juice. It does take a little bit more efforts, but using real fresh squeezed lemon juice is better in the end.
- Avoid overmixing the crust. This will lead to a dense instead of a flaky finished crust.
- Make sure to bake the crust before AND make sure it’s semi-cool before adding the custard.
- Sift sugar and flour in custard to prevent clumps from forming in the filling.
- Use parchment paper. Cooking spray will work just fine, but for easier removal and more leverage when cutting the squares, line the pan with parchment paper before baking the shortbread crust.
- Let the custard cool completely before dusting and cutting the squares. This will prevent the dusting sugar from melting into the squares and will help with cleaner cuts.
- Use a glass baking pan. For lemon squares, glass is considered better than metal pans because the acidity of the lemon juice can react with the metal, which can give the bars a metallic taste.
How to store lemon squares
- Store the baked and cooled lemon squares in an airtight container in the fridge, although they can be left out for a few hours while they are being served. They will last around 3-5 days in the fridge.
- To freeze the lemon squares: place the completely cooled cookies, on a cookie sheet, freeze for 1 hour then transfer to a freezer safe container, place parchment paper between the layers. They will keep for up to 3-4 months in the freezer. Be sure to thaw the frozen squares in the fridge for at least a day before serving. If you are planning on freezing them, don’t dust with powdered sugar first, that can be added right before serving.
Ways to adjust your lemon squares
- Use different fruit juices. Grapefruit, lime, and blueberry squares have been the delicious variations I’ve tried so far, but I think any fruit juice that has been strain of seeds and pulp can be used for the custard.
- Adding finely grated lemon zest is optional, and can be added to the both the crust and custard or either of the two to add bright pops of lemon flavor throughout.
- Sprinkle in a pinch of cayenne pepper for lemon squares with a bit of spice.
Lemon Squares
This lemon squares recipe has just 8 ingredients and 10 minutes of prep! The lemon curd filling is sweet and sour and sits on top of a flaky, buttery shortbread crust for a simple and delicious treat.
Servings 15 servings
Equipment
- Cooking spray
- 9x13" cake or roasting pan
- Food processor
- Stand or electric hand mixer
- Sift
- Microplane
Ingredients
For the crust:
- 2 cups all-purpose flour
- 1 cup unsalted butter cold
- ½ cup confectioners' sugar
- Pinch of salt
For the custard:
- 2 cups white sugar
- 4 eggs
- ¼ cup all-purpose flour
- ¼ cup lemon juice or more to taste
- 1 teaspoon baking powder
- 1 teaspoon grated lemon zest or to taste (Optional)
- confectioners' sugar for dusting
Instructions
Make shortbread crust and bake
- Preheat the oven to 350 degrees F (175 degrees C). Coat a 9x13-inch baking dish with cooking spray.
- Combine 2 cups of all-purpose flour, unsalted butter, and 1/2 cup powdered sugar in the bowl of a food processor; pulse until mixture resembles coarse crumbs. Press the mixture into the prepared baking dish. TIP: Use the bottom of a measuring cup to press evenly.
- Bake in the preheated oven until crust edges are golden brown, 18 to 22 minutes. Cool to room temperature.
Make custard filling
- Beat white sugar, eggs, 1/4 cup of flour, lemon juice, baking powder, and lemon zest together in a bowl using an electric mixer until light and fluffy; pour onto the cooled crust.
- Each lemon should result in about 3-4 tablespoons of juice so 1-2 lemons should be enough for the 1/4 cup of lemon juice needed in the custard.
Bake custard and coat with sugar
- Bake in the oven until custard is set, 25 to 28 minutes. Completely cool lemon squares; dust top with confectioners' sugar and serve.
