2Egg Yolkat room temperature, medium to large size
80gr (1/3 cup)Caster Sugar
80ml (1/3 cup)Lemon Juice
10gr (1 tablespoon)Cornstarchoptional
45gr (3 tablespoons)Unsalted Buttercubed
Butter Cookies
180gr (3/4 cup)Unsalted Buttervery soft, at room temperature
75gr (3/4 cup)Icing Sugarsifted
1Lemon, Zestedabout 1 teaspoon of lemon zest
1Egg Yolkat room temperature, medium to large size
225gr (1 1/2 cup)Plain / All-Purpose Flour
Instructions
Lemon Curd
In a small saucepan, combine the Lemon Juice, Egg Yolks, Sugar and optionally the Cornstarch. Whisk to combine then turn on very low heat. Keep on whisking for about 5 minutes, or until the liquid starts to slightly thicken (See note 1).
Slowly add the cubed Butter a little bit at the time, waiting until they have melted and are fully incorporated before adding more.
Continue to cook on very low heat for about 10 minutes or until the curd has thickened, while continuously stirring (see note 2).
Optionally, pour the cooked lemon curd through a thin mesh sieve to remove any bits of cooked egg or lumps.
Transfer into a clean jar and pace in the fridge to chill for at least 2 hours.
Butter Cookies
Place the soft Butter, Icing Sugar and Lemon Zest in a large bowl (if using a hand mixer) or in the bowl of your stand mixer fitted with the paddle attachment. Cream the butter and sugar for 2 to 3 minutes or until creamy and smooth (see note 3).
Add the Egg Yolk and slowly mix it in until fully incorporated.
Add the Flour and slowly mix it in until a rough cookie dough comes together (see note 4). Bring the dough together and place it between two sheets of baking paper.
With a rolling pin, roll the dough to be about 4mm thick (about 1/8 inch). Place in the fridge to chill for at least 1 hour. Take out of the fridge and remove the top piece of baking paper.
With a 6mm (2,5 inch) wide round or fluted cookie cutter, cut out the cookies. With a slightly smaller cookie cutter (I used a 45mm / 1,5 inch wide one), cut out the centre of half of the cookies.
Gently lift the cut out cookies (I used a small offset spatula) and place them on a large baking tray prepared with baking paper or a baking mat (see note 5). Any leftover dough can be re-rolled, chilled and used to make more cookies.
Place the tray in the fridge to chill for 30 minutes and preheat your oven on 160 degree Celsius or 325 degree Fahrenheit.
Bake for 13 to 15 minutes or until lightly golden. Take out of the oven and leave to chill over a wire rack until completely cool.
Assembling the Cookies
Pour a little bit of Lemon Curd over the full cookies (the ones without the cutout part) (see note 6). Spread it around the cookie slightly.
Place the top cookie (with the cutout centre) over the curd and gently press until it sticks and the curd has reached the edges of the cookies.
Serve straight away or store in the fridge until ready to serve.
Notes
For more information on how to make the curd, check out my Tangy Lemon Curd recipe.
Avoid using an aluminium saucepan to cook the curd as it could react with the lemon juice and give it a metallic taste.
To know the lemon curd has cooked, dip the back of a spoon in the curd and draw a line into the curd with your finger. Tip the spoon down and see if any of the curd is dripping down over the line. If the line stays clear, the curd is cooked. You can also check with a thermometer: it is ready when the curd reaches around 82'C/180'F.
No need to cream the butter and sugar for a long time here, we are not trying to incorporate air bubbles into the mixture. Simply make sure there are no more lumps of unmixed butter, which can sometimes happen when the butter is too cold.
To know it is mixed enough, press some of the dough between your hands. If the crumbs stick together, the dough is ready.
I used a perforated tray with perforated baking mat for an even baking.
I used about half a tablespoon of curd for each cookie