A smooth, very lemon-tart filling with an easy poppy seed shortbread crust
Servings: 12bars
Calories: 267kcal
Ingredients
Shortbread crust
1cupall-purpose flour5 ounces
¼cupgranulated sugar
½teaspoontable salt
1-2tablespoonpoppy seeds
8tablespoonunsalted buttermelted
Lemon filling
1cupgranulated sugar
2tablespoonall-purpose flour
2teaspooncream of tartar or lemon powdersee note
¼teaspoontable salt
3large eggs
3addtional large egg yolks
1tablespoonlemon zest
⅔cupfresh squeezed lemon juiceabout 4 lemons
4tablespoonunsalted buttercut into small pieces
To serve
2-4tablespoonpowdered sugar
Instructions
Prepare ahead
Preheat oven to 350°F and put the rack in the middle.
Line an 8-inch square pan with foil that comes up over the edges. This will be used to pull the bars out of the pan after baking. Smooth out the foil as much as possible so the edges of your bars look nice.
Make the crust
Whisk dry ingredients: whisk 1 cup flour, ¼ cup sugar, ½ teaspoon salt, and 1-2 tablespoon poppy seeds in a bowl.
Add melted butter: add 8 tablespoon melted butter to the bowl and stir to combine. The mixture will be a little crumbly.
Press crust into pan & bake: press the crust mixture into the foil-lined pan. Bake for 18-24 minutes, until golden or dark brown (either option works, see picture). Rotate the pan half way through baking for even baking.
The filling is made while the crust bakes, then it is poured onto the still-hot, browned crust.
Make the filling
The filling takes about 15 minutes to make and should be done while the crust bakes.
Whisk dry ingredients: whisk 1 cup sugar, 2 tablespoon flour, 2 teaspoon cream of tartar, and ¼ teaspoon salt in a bowl.
Add eggs: add in the 3 eggs and 3 additional yolks, and whisk to combine until no streaks of egg remain.
Add lemon: add in 1 tablespoon lemon zest and ⅔ cup of juice, and whisk to combine.
Cook in saucepan & stir constantly: transfer the mixture into a saucepan and cook over medium-low heat (you don't want to overcook the eggs). Stir constantly until the mixture thickens into a pudding-like consistency and is 160°F. This should take about 5-10 minutes.
Add butter & strain: remove the mixture from the heat and stir in 4 tablespoon of cut-up butter pieces (they need to easily melt in the slightly warm mixture). Strain through a fine-mesh strainer (optional, but doing this makes for a perfect looking bar).
Assemble the bars & bake
Pour filling into pan & bake for 8-12 min: pour the filling over the still-warm crust, slightly tilting the pan to evenly spread the filling around. Bake in the 350°F oven for about 8-12 minutes - until the filling is set and barely jiggles when shaken. If you want to use an instant-read thermometer, it is done when the center is 175°F. (You can cover the thermometer hole with powdered sugar).
Cool completely: The bars need to cool completely, 1-2 hours. After they cool on the counter for an hour, you can also pop them in the fridge. Do not dust with powdered sugar until you are ready to serve (the sugar absorbs into the top quickly).
Store in the fridge, since these are a custard-based dessert. They can sit on a counter for several hours when serving.
Dust with powdered sugar right before serving.
Notes
Cream of tartar or lemon powder add extra tartness that really make the lemon flavor jump out at you (more than simply adding extra zest). This is optional but really makes this recipe stand out when added.Bake crust until light or dark golden brown: I've baked this crust many times, sometimes I take it out when it is light golden brown (left) and sometime dark golden brown (right). The flavor and texture seem unaffected and both work.