Sometimes you just nail it. These cookies have the perfect texture with the right amount of sweetness and crumble, paired with a zingy Key Lime curd filling. It’s the perfect twist on a classic Linzer cookie.
These cookies are perfect for enjoying at home for the holidays, or for dropping off for your family and loved ones. You can also switch up the fillings and cut-out window designs to keep them seasonal and in rotation all year round.
This sandwich cookie is based on the traditional Linzer cookie, which is normally made with a raspberry jam filling.
Here, you’ll learn how to make a key lime curd, but if you can’t find key limes where you live, you can easily use regular limes, lemons, or any type of available citrus. They will be just as delicious, I promise.
Let’s get started!
We start out with making our curd, so that it has plenty of time to cool and set. You can make the curd several days in advance. It will keep for up to 2 weeks sealed well in the refrigerator.
You can also make the cookies in advance: it’s worth noting that they require at least 2 hours to chill after mixing the dough, and up to 24. They can be baked a day ahead. Just hold off on the sugar dusting until you are ready to assemble and serve.
You do need some special equipment for these cookies. I recommend using a 2″-2 1/4″ fluted cookie cutter, and 1/2″ decorative cutters for the window pieces. If you don’t have a larger cutter, you could also use a glass, or something that is roughly 2″ in diameter.
Making the curd
Making a citrus curd may seem very daunting, but it is very simple. It’s actually one of the first things I learned to make in the dessert world! This recipe includes gelatin, which is only to help stabilize the curd within the cookie sandwich. It is not strictly necessary and can be omitted for dietary restrictions. Please be aware that your curd will set a bit more loose and may be a little bit more messy, but delicious nonetheless.
There are several different ways to make a curd. Many people recommend using a double boiler method, but I don’t find that to be necessary, and it can be intimidating if you have not used one before. You can get a perfectly silky smooth curd without any extra bowls! Here are a few tips to help you if it is your first time making a curd:
Tips for making the perfect lime curd
- Get your mise en place ready ahead of time! Mise en place means “setting up”– it is very helpful with things like curd that tend to move quickly once the get going, to have all of your recipe elements laid out and ready to go, so you are not searching for anything at an inopportune time.
- Dissolve your sugar and salt well in the lime juice. Let the mixture thoroughly heat up before you add your eggs.
- Whisk your eggs WELL! Whisk like you’ve never whisked before! This minimizes the risk of any lumpy areas of scrambled egg. And speaking of whisking….
- Make sure to whisk constantly and confidently once you add the eggs to the hot juice and sugar. Keep an eye on the edges of the pot, because that is where things start to burn quickly. Pour in the eggs slowly so they don’t scramble.
- If you do end up with a couple scrambled eggs, that’s okay! Just make sure to take good care when passing your finished curd through the sieve at the end. Scrambled eggs who?! Not here! No one will ever know!
- After adding the eggs, once it starts to thicken, it will thicken very quickly. If you can pass your finger through the curd on the back of a wooden spoon and it leaves a clean line, it’s ready to go!
- When in doubt, cook over a low heat. You can always cook your curd for longer, but you can’t take it back if it cooks too fast and burns.
- When adding in the butter, make sure all lumps are gone before stirring in the gelatin.
The butteriest cookies ever
Linzer cookies traditionally contain some type of nut flour. For these, I decided to use Hazelnuts to pair with the tartness of the lime. Toasting them before grinding gives them an extra depth of flavor that really compliments the sharp taste of the curd.
We start off the base of our cookie dough with creaming together the butter and sugar, then incorporating wet ingredients. Then we slowly add in our dry ingredients, being very careful not to over mix the dough.
Then, we divide the dough into two disks, wrap them in cling wrap or your favorite cling-wrap alternative, and let it hang out in the fridge for 2-24 hours to let the butter firm up.
The trick for any cookie dough that has a high percentage of butter is to keep it very cold. As long as this dough is properly chilled, you will not need extra flour for rolling it out, which can change the final texture of the cookie. Over-handling will also change the texture of the cookieou will end up with a tougher cookie that doesn’t have the signature delicate butteriness of a Linzer.
A few tips
My trick for not over-handling these cookies, which require a fair amount of cutting out, is to roll out the dough on the piece of parchment paper it will be baked on, and to cut out the cookie shapes without removing it from the paper. This way, the dough gets minimally handled and you can just slide the parchment onto your baking sheet when you’re ready to bake! Easy as that.
If at any point the dough starts feeling greasy, sticky, or too soft, this is a sign that your butter is melting. Pop it in the fridge for 15 minutes or so to firm it back up before working with it again.
Are you ready to make the most fun and festive cookies you’ve ever tried? Let’s give it a go!
If you love this recipe, be sure to share it, and tag me on instagram so I can see your bakes, and leave a comment below!