You know the old adage, “Rules are made to be broken”? Yes, well I think a similar one applies to recipes. Something like, “Recipes are made to be altered”. Apparently, Rose Levy Beranbaum spent some time developing the perfect lemon curd slice, fittingly naming it The Ultimate Lemon Butter Bar. Similar to the ubiquitous lemon bars but in her recipe the lemon topping is cooked first before adding it to the already baked shortbread base. Completely awesome! After making her version, I decided to completely re-write it and include Ina Garten’s method as well! Talk about messing with perfection! Like I said, there’s an unspoken rule…
I’ve been searching for just such a recipe for 10 years now, since coming back from Thailand where I sampled the perfect lemon curd slice. Although most Thai (and other Asian) desserts tend to be coconut-based, there was a bakery next door to our office that sold American-style pies and desserts, and where my colleagues and I would go from time to time for special occasions. There was Rhubarb pie, and Lemon Curd Slice, and… many other goodies, but my memory fails me, because I bought Lemon Curd Slice every time! I was so consistent that, at the airport on my day of departure my colleague came bearing a piece as my farewell gift!
I haven’t found anything similar in any restaurant or dessert bar since. Sure, there are citrus tarts sold at most cafes, which are certainly delicious, and more lemon tart recipes than you can poke a stick at, but this one is mine. I wasn’t convinced about the buttery shortbread base featured in Rose’s version (too hard), so have used a gluten-free version of my Kiwifruit, Lime and Coconut Slice as a base, and a rich, tangy lemon curd recipe as a topping. Don’t be put off by the fancy-sounding title; this really is just a simple lemon curd baked atop a buttery shortbread base. Without further ado, here it is; The Ultimate Lemon Curd Slice.
The Ultimate Lemon Curd Slice {gluten-free}
Makes 9 large squares or 16 small*
Ingredients
For the crust
2/3 cup (75g) plain (all-purpose) gluten-free flour
¼ cup (35g) brown rice flour
¼ cup (56g) gluten-free cornflour (corn starch)
¼ teaspoon salt
¼ teaspoon baking powder
100g (7 tablespoons) unsalted butter, softened*
1/3 cup (75g) caster (super-fine) sugar
2 teaspoons finely grated lemon zest
1 egg yolk
For the lemon curd
2 large eggs
2 egg yolks
¾ cup (165g) caster sugar
1/3 cup (80g) chilled unsalted butter
Finely grated zest and juice of 2 lemons
2 tablespoons icing sugar for dusting
Method
For the shortbread base, preheat the oven to 180°C/350F. Grease a 20 cm (8 x 8-inch) square baking pan and line with baking paper, leaving 5 cm overhang.
In small bowl, whisk together gluten free flour, rice flour, cornflour, salt, and baking powder. In bowl of stand mixer fitted with paddle attachment, or with an electric hand beater, cream butter, sugar and lime zest together on medium-low speed, until a thick paste forms, about 30 seconds. Add egg yolk and beat. Add dry ingredients and beat until a dough forms, about three minutes. Press into prepared baking dish.
Bake crust in the preheated oven for 15 to 20 minutes, or until light golden brown.
While the base is baking, prepare the Lemon Curd Topping.
Remove the zest from lemons with fine grater or microplane. You should have about 2 tablespoons. Squeeze lemons to make up 1/3 cup of juice. Whisk whole eggs, yolks and sugar in a saucepan until smooth, then place pan over low heat. Add the butter, lemon juice and zest and whisk constantly until thickened. Strain through a sieve into a heatproof bowl. Allow to cool.
When the base is baked, remove it from the oven, and immediately pour the warm lemon curd on top of the hot biscuit base.
Cool the lemon curd slice completely in the pan on a wire rack. Refrigerate the pan overnight to set the lemon curd completely before cutting into bars. Place the icing sugar in a strainer and tap the strainer with a spoon to sprinkle a thick, even coating, entirely covering the lemon.
Run a thin bread knife between the sides of the pan and the pastry on the two sides without the baking paper. Use the paper to lift out the lemon curd–covered shortbread onto a cutting surface. Use a long, sharp knife to cut the shortbread, wiping the blade after each cut.
*To serve as dessert, cut into 9 (3×3) even squares; to serve as a snack, cut into 16 (4×4).
The icing sugar will start to be absorbed into the lemon curd after several hours, but it can be reapplied before serving.
Store in an airtight container at room temperature, or in the refrigerator or freezer.
Notes
Inspired by Rose Levy Berenbaum
My niece loves lemon bars and I will make them for her when she visits me. I am glad I stumbled upon your blog. I enjoy reading it and your photos are stunning.
Hi Gerlinde, thank you for your kind comments! I hope you enjoy making many of these recipes. 🙂