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These melt-in-your-mouth thumbprint cookies are like miniature key lime pies. Though I use regular limes to make the lime curd because who wants to zest that many key limes!? The buttery cookie dough is very easy to whip up with basic pantry ingredients and a bit of cornstarch to keep the cookies tender. Finally, to bring the key lime pie vision to life, I finish the cookies off with a glossy meringue and some crumbled graham crackers. Both toppings are optional, but they are a fun and easy way to elevate a thumbprint cookie to party-worthy.

It took me months to develop these thumbprint cookies with lime curd! I knew when my lemon thumbprint cookies were a hit, that I had to make a lime version as well. Plus, I’ve been wanting to make a lime curd recipe for years. And I’ve gotta say—it really rivals a homemade lemon curd.

Through the many, and I mean many, rounds of recipe testing I tried all kinds of things—the amount of lime zest in the curd and the cookie dough, rolling dough balls in graham cracker crumbs, mixing graham cracker crumbs into the dough, baking the cookies on graham crackers (questionable at best)! The list goes on.

The resulting recipe is the formula that is the best overall. Best texture, best zesty but not bitter flavor, and the most streamlined process.

Flour, sugar, limes, salt, cornstarch, cream of tartar, brown sugar, vanilla, egg whites, egg yolks, an egg, and butter all set out on a green surface.

Key Ingredient Notes

There are few specialty ingredients in this recipe. But here are a few helpful notes:

Limes: you’ll need quite a few limes for this recipe, which is why I wanted to steer clear of key limes. You’ll need 7–8 regular limes to get the correct amount of lime zest. That being said, if you want to use key limes to make these, go for it!
Eggs: to ensure you get enough lime curd to fill all the cookies, make sure you’re using eggs labeled as “large.”
Butter: for these cookies, use standard grocery store butter. Do not use European-style butter. The higher fat content will cause the cookies to spread out more during baking.
Cream of tartar: if you plan to make the meringue topping with the leftover egg whites, you’ll need some cream of tartar to stabilize and add volume to the egg whites.

Let’s Walk Through The Process

Make the Lime Curd

A saucepan with eggs, egg yolk, sugar, grated zest, and lime juice mixture set on a green surface.

Whisk together the yolks, egg, sugar, lime zest, lime juice, and a pinch of salt.

Cooked lime curd in a saucepan with a whisk set inside, butter set in a bowl nearby.

Cook over low heat, stirring constantly with a whisk or rubber spatula, until mixture thickens and registers 160°F, about 4 minutes.

Lime curd straining through a fine mesh sieve with an empty saucepan set nearby.

Lime curd in a glass bowl with a fine mesh sieve of strained out lime zest set nearby.

Stir in the butter then strain through a fine mesh sieve.

Sugar, brown sugar, butter and lime zest in a mixing bowl.

Beat the butter until smooth, then add the sugars and lime zest and beat until creamy.

A mixing bowl with cookie dough set on a counter with a spoon set in th bowl. Mixer paddle attachment, flour and cornstarch set around.

Add an egg yolk, lime juice, salt, and vanilla and mix to combine.

Cookie dough in a metal mixing bowl with a paddle attachment and spatula on a green countertop.

Add the flour and cornstarch and mix just until combined.

Four unbaked cookie dough balls, one with a thumbprint, on a sheet of parchment paper.

Scoop and roll dough into balls then gently press an indent in the center of each dough ball; chill until firm.

Fill the Cookies and Bake

Seven unbaked lime curd thumbprint cookies on a parchment-lined baking sheet.

Fill dough balls with lime curd.

Lime thumbprint cookies cooling on a black wire rack over a green surface.

Bake just until the edges are set and starting to turn golden brown.

Optional: Finish with Meringue and Graham Cracker

Egg white and sugar in a glass bowl set over a saucepan.

Whisk together the reserved egg whites, sugar, and cream of tartar.

Cooked egg white and sugar meringue in a glass bowl with a whisk set over a saucepan.

Cook over a pot of simmering water until it reached 160ºF.

Whipped egg white meringue on a whisk set over a mixing bowl.

Whisk in vanilla then whisk on high speed until stiff peaks form.

Round cookies with yellow centers and toasted meringue on top, cooling on a wire rack over a green surface.

Pipe meringue over top, torch to toast, then top with a piece of graham cracker. If you don’t have a kitchen torch, this is the one I have and use all the time!

Lime thumbprint cookies topped with toasted marshmallow and graham cracker pieces on a wooden board.

Tips from Recipe Testing

Many recipes will have you chill the dough before rolling into balls. The problem with this is you have to let the dough soften at room temp before you can scoop it. This makes no sense! While the dough is still soft, scoop and roll it into balls. Form the indent in each dough ball, then chill the dough.
Rolling and indenting the dough prior to chilling will also help mitigate any cracking around the edges. Some cracking may happen, but it’s easier to fix when the dough is still somewhat warm/pliable.
I find the easiest way to fill the wells is to spoon the curd into a small zipper-lock bag, snip the corner of the bag, and pipe the curd into the wells.

Lime thumbprint cookies topped with toasted meringue and graham cracker pieces on a wooden board.

Round thumbprint cookie filled with yellow lime curd, some topped with meringue and graham cracker, sitting on a wooden board with crumbs scattered around.

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