Lemon Bars
Crisp, buttery shortbread, tangy lemon custard, and a dusting of powdered sugar – these classic lemon bars are irresistible. Each decadent bite delivers a burst of lemony sunshine. The soft filling is sweet and tangy, and the cookie base is crisp around the edges and tender in the middle – definitely the best lemon bars you’ve ever tasted.
This recipe was written for the Arizona Republic.
Lemon bars are not difficult to make, and they require very few ingredients. That said, because the tasty treat boasts a short ingredient list, the components matter. To ensure lemon bar perfection, I have a few suggestions.
Use fresh lemon juice. This advice is non-negotiable. Since lemon bars get the bulk of their flavor from lemons, you must use freshly squeezed juice from ripe lemons.
Do not consider using bottled lemon juice or lemon juice concentrate as a time-saver, it simply won’t produce the same result. Plus, you need lemon zest, so fresh lemons are required no matter how you slice it.
Note, use only 1 cup of lemon juice as directed; if you add more, the custard will not set up properly. Pro tip: Zest the lemons before you juice them and use room temperature lemons to ensure you get the maximum amount of juice from each one.
Use unsalted butter: Since the amount of salt varies from one butter manufacturer to another, it’s nearly impossible to predict how salty your baked goods will turn out when using salted butter. For that reason, I prefer using unsalted butter so I can add only what’s needed to balance flavor. If you only have salted butter, omit the salt in the recipe. Pro tip: I prefer European style butter for this recipe; the higher butterfat leads to a richer, more buttery shortbread. If you don’t have European style butter, American style butter will do.
Use large eggs. The filling for lemon bars is an egg-based custard. The eggs add richness while helping the custard thicken, and the measurements need to be precise. Pro tip: Use room temperature eggs; at room temp, the yolks will break more easily and mix more evenly with the egg whites and other ingredients in the filling.
Don’t balk at the amount of sugar! The custard layer requires 3 cups of granulated sugar to balance the tanginess of the lemons (we never said this was a low-cal dessert). Note: When using sweeter Meyer lemons, reduce the granulated sugar to 2 cups
Line your baking dish. Shortbread tends to stick to most baking pans. This is true of both glass and metal pans. To ensure effortless removal of the bars from the pan (and perfectly sliced lemon bars), line your baking dish with parchment paper or foil so you can remove the whole batch from the pan before slicing.
Note: Glass pans bake faster than metal plans which is why the cooking time below has a 10-minute range.
Pro tip: Parchment paper is my first choice for lining the pan; aluminum foil can stick to the shortbread and tear.
Don’t overcook your lemon bars. Lemon bars continue to set as they cool, so pull them from the oven when the center jiggles slightly when you shake the pan. I don’t mean a wobbly center; the goal is a center that’s almost set, but not quite. Don’t panic if you see little brown spots on the surface; these are delicious, caramelized air bubbles. Froth is formed when we whisk the eggs, and those bubbles rise to the surface and brown in the oven. They are easily covered up with powdered sugar.
Let your lemon bars cool before slicing. As mentioned above, lemon bars set as they cool. They first need to cool at room temperature for 1 hour and then in the refrigerator for a minimum of 2 hours.
Use a damp knife for slicing. Lemon bars are sticky so to ensure flawless slices, dampen a very sharp knife before cutting and clean/re-wet the knife between every slice. Pro tip: Cut straight down into the bars to cut the shortbread; try not to slide the knife as it will cling to the custard.
Consider making these lemon bars in advance. Since lemon bars need to cool for a minimum of 3 hours, they make an excellent make-ahead dessert. When baking the bars in advance, cool to room temperature, cover the pan with plastic wrap and refrigerate for up to 4 days, or freeze for up to 3 months (add an extra layer of plastic wrap when freezing). Do not dust the bars with powdered sugar until ready to serve. Pro tip: The lemon custard doesn’t fully solidify in the freezer so there’s no need to thaw the bars before serving.
Lemon Bars
Ingredients
For the Shortbread Crust
- 2 1/2 cups all-purpose flour
- 2/3 cup powdered sugar, plus more for dusting
- 1/2 teaspoon salt, omit the salt if you’re using salted butter
- 12 tablespoons butter, 1 1/2 sticks, melted, regular or European style butter
- 1 teaspoon vanilla extract
For the Lemon Filling
- 7 large eggs, room temperature
- 3 cups granulated sugar, or 2 cups if you’re using Meyer lemons
- 1 cup fresh lemon juice, from 5 to 8 lemons, depending on size
- 3 tablespoons fresh lemon zest, from 3 to 5 lemons, depending on size
- 1 cup all-purpose flour
Instructions
- Preheat the oven to 350 degrees. Line a 9×13 inch baking dish with parchment paper.
- To make the shortbread crust, in a large bowl, whisk together the 2 1/2 cups of flour, powdered sugar and salt. Add the melted butter and vanilla and stir with a spatula until blended (the mixture will be crumbly). Transfer the dough to the prepared pan and press into a flat, even layer.
- Bake for 15 to 20 minutes, until light golden.
- Meanwhile, to make the filling, in a large bowl, whisk together the eggs and granulated sugar until blended. Add the lemon juice and lemon zest and whisk to combine. Whisk in the 1 cup of flour and whisk until smooth and blended, with no traces of flour.
- Pour the filling over the warm crust. Bake for 25 to 35 minutes, until the filling is almost set (to prevent over-baking, remove the pan from the oven as soon as the filling is slightly jiggly in the center).
- Cool in the pan, on a wire rack, at room temperature for 1 hour, then refrigerate for at least 2 hours.
- When ready to serve, use the parchment paper to lift the bars from the pan and transfer them to a cutting board. Dust with powdered sugar and cut into 18 to 24 bars using a clean, sharp, damp knife. Clean and re-wet the knife after each cut.
- Store leftovers in an airtight container in the refrigerator for up to 4 days or freeze for up to 3 months. There’s no need to thaw frozen lemon bars. Dust with more powdered sugar before serving if desired.