I wrote a Key lime cookie recipe for my Key Lime Cooler Cookies that are buttery, bursting with fresh key lime flavor and cloaked in powdered sugar, and I’m sharing one simple secret ingredient that makes them a standout for holiday baking.

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I stumbled onto these Key Lime Cooler Cookies last winter and they kept showing up at every party I went to, so I had to figure out why. Flaky little rounds cloaked in powdered sugar that somehow hide a sharp, fresh kick from key lime zest, they make people stop mid bite and ask what the secret is.

I cant honestly say theres one secret, but the contrast of bright lime and that snowy coating will make you curious enough to bake a batch. If you like tangy surprises, this Keylime Cookie Recipe might just ruin store bought cookies for you.

Ingredients

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All purpose flour: gives structure, carbs and some fiber, makes cookies tender
Unsalted butter: adds richness, fat and flavor, helps spread n brown
Granulated sugar: sweetens, adds crunch and caramel notes, mostly simple carbohydrates
Powdered sugar: extra sweetness and smooth coating, makes that powdered snow finish
Egg: binds ingredients, adds protein and moisture, helps cookies hold shape
Key lime zest: bright citrus oils for aroma and punch, adds slight bitterness
Key lime juice: provides tangy acidity that balances sweetness and gives fresh lime flavor
Cornstarch: softens texture, lowers gluten toughness, creates delicate melt in your mouth cookies

Ingredient Quantities

2 1/2 cups all purpose flour

1 teaspoon baking powder

1/4 teaspoon salt

2 tablespoons cornstarch

1 cup unsalted butter softened

1/2 cup granulated sugar

3/4 cup powdered sugar plus about 1 cup more for coating

1 large egg

1 teaspoon vanilla extract

1 tablespoon finely grated key lime zest

2 tablespoons fresh key lime juice

How to Make this

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1. Preheat oven to 350°F (175°C) and line a baking sheet with parchment paper, rack in the middle of the oven.

2. Whisk together 2 1/2 cups all purpose flour, 1 teaspoon baking powder, 1/4 teaspoon salt and 2 tablespoons cornstarch; set aside.

3. In a large bowl beat 1 cup softened unsalted butter with 1/2 cup granulated sugar and 3/4 cup powdered sugar until light and fluffy, about 2–3 minutes with an electric mixer or a good arm workout.

4. Mix in 1 large egg, 1 teaspoon vanilla extract, 1 tablespoon finely grated key lime zest and 2 tablespoons fresh key lime juice until combined.

5. Add the dry ingredients to the wet in two additions and stir just until no streaks of flour remain; don’t overmix or the cookies will get tough.

6. Chill the dough for at least 30 minutes in the fridge (helps them keep shape and brightens the lime flavor), or up to 2 hours.

7. Scoop rounded tablespoonfuls (or a small cookie scoop) and roll into balls, place about 2 inches apart on the prepared sheet; if dough is rock hard let it sit 5 minutes to soften.

8. Bake 10 to 12 minutes until edges are set and centers still look slightly soft; they firm up as they cool, so avoid browning.

9. Let cookies cool on the sheet 4 to 5 minutes, then roll each warm cookie in about 1 cup powdered sugar to coat. Transfer to a wire rack to cool completely and roll again for a thicker snowy cloak.

10. Store in an airtight container at room temp for up to 3 days, or freeze for longer; pro tip: more zest equals more punch, so add a little extra if you want a brighter lime kick.

Equipment Needed

1. Oven set to 350°F (rack in middle)
2. Baking sheet lined with parchment paper
3. Two mixing bowls, one large for butter/sugar and one medium for dry ingredients
4. Electric mixer or a good whisk if you wanna do it by hand
5. Measuring cups and spoons for flour, sugar, cornstarch, juice etc
6. Microplane or fine grater for the key lime zest
7. Tablespoon or small cookie scoop for portioning and rolling balls
8. Wire cooling rack to cool and roll cookies in powdered sugar
9. Airtight container or freezer safe bag for storing leftovers

FAQ

Why did my cookies spread too much and come out flat? Usually the butter was too soft or the dough was warm, or you didnt chill the dough before baking; try chilling the scooped dough 30 to 60 minutes, measure butter by weight not volume, and bake on a cool baking sheet so they keep shape.

How do I get a bright key lime flavor without making the dough too wet? Use finely grated key lime zest for the most citrus oil, then add the juice to taste; zest gives the punch, juice gives tang, so dont overdo the liquid and fold gently so the dough stays tender.

Can I use regular limes or bottled lime juice instead of key limes? Yes, Persian limes work fine but theyre less floral so use a bit more zest; bottled key lime juice is okay in a pinch but fresh zest still makes the biggest difference.

Why is there cornstarch and powdered sugar in the dough, what do they do? Cornstarch lightens and tenderizes the cookie crumb so theyre melt in your mouth; powdered sugar in the dough and for coating helps give a soft, snowy finish and a finer texture than granulated sugar.

When should I roll the cookies in powdered sugar so it sticks correctly? Roll them while the cookies are still a little warm but not piping hot, then let them cool and dust again for a nicer coating; the first warm roll helps the sugar adhere.

How should I store or freeze these cookies? Store in an airtight container at room temp for 3 to 4 days, refrigerate up to a week if you prefer, or freeze baked cookies up to 2 to 3 months; you can also freeze shaped dough balls on a tray then bag them and bake from frozen, adding a minute or two to the bake time.

Can I make these without an egg for allergies or vegan needs? Yes, try a flax egg (1 tbsp ground flax + 3 tbsp water, let sit 5 min) or 3 tbsp aquafaba; texture will be a bit different and maybe more crumbly, so handle gently and dont overbake.

Key Lime Cookies Recipe Substitutions and Variations

All purpose flour: swap for an equal amount 1-to-1 gluten free flour blend (use the same 2 1/2 cups). If your blend lacks xanthan gum add 1/4 tsp for structure, otherwise cookies can turn crumbly.
Unsalted butter: use 1 cup salted butter and skip the 1/4 tsp salt in the recipe, or for a dairy free version use 1 cup vegan stick butter 1:1 (chill a bit before creaming).
1 large egg: make a flax egg — 1 tbsp ground flaxseed + 3 tbsp water, let sit 5 minutes — or use 1/4 cup unsweetened applesauce for a softer, slightly denser cookie.
Key lime zest + juice: use regular Persian limes in the same amounts, or 2 tbsp bottled lime juice + 1 tbsp bottled lime zest if fresh limes aren’t available, though fresh will be brighter.

Pro Tips

1) Zest into the sugar first. Rub the lime zest into the granulated sugar with your fingers until it smells insane, the oils come out and the whole cookie tastes brighter. It makes a bigger difference than you’d think.

2) Weigh the flour if you can. 2 1/2 cups all purpose flour is about 312 grams. Spoon and level if you must, but weighing stops dry, dense cookies and saves you from guessing.

3) Chill and freeze tricks for shape and texture. Chill the dough at least 30 minutes, and if you want puffier, thicker centers freeze the rolled balls 10 to 15 minutes before baking. Also try baking one tray at a time on the middle rack for the most even bake, and use an oven thermometer if your oven is old or unpredictable.

4) Make the powdered sugar coating pop. Sift the powdered sugar first so it coats smooth, and stir in a teaspoon of extra zest or a tiny pinch of salt to balance the sweetness. Roll once warm and again when cool for that snowy look, then store layers separated by parchment so they dont stick.

Key Lime Cookies Recipe

Recipe by Dave Simpson

0.0 from 0 votes

I wrote a Key lime cookie recipe for my Key Lime Cooler Cookies that are buttery, bursting with fresh key lime flavor and cloaked in powdered sugar, and I'm sharing one simple secret ingredient that makes them a standout for holiday baking.

Servings

servings

Calories

173

kcal

Equipment: 1. Oven set to 350°F (rack in middle)
2. Baking sheet lined with parchment paper
3. Two mixing bowls, one large for butter/sugar and one medium for dry ingredients
4. Electric mixer or a good whisk if you wanna do it by hand
5. Measuring cups and spoons for flour, sugar, cornstarch, juice etc
6. Microplane or fine grater for the key lime zest
7. Tablespoon or small cookie scoop for portioning and rolling balls
8. Wire cooling rack to cool and roll cookies in powdered sugar
9. Airtight container or freezer safe bag for storing leftovers

Ingredients

2 1/2 cups all purpose flour
1 teaspoon baking powder
1/4 teaspoon salt
2 tablespoons cornstarch
1 cup unsalted butter softened
1/2 cup granulated sugar
3/4 cup powdered sugar plus about 1 cup more for coating
1 large egg
1 teaspoon vanilla extract
1 tablespoon finely grated key lime zest
2 tablespoons fresh key lime juice

Directions

Preheat oven to 350°F (175°C) and line a baking sheet with parchment paper, rack in the middle of the oven.
Whisk together 2 1/2 cups all purpose flour, 1 teaspoon baking powder, 1/4 teaspoon salt and 2 tablespoons cornstarch; set aside.
In a large bowl beat 1 cup softened unsalted butter with 1/2 cup granulated sugar and 3/4 cup powdered sugar until light and fluffy, about 2–3 minutes with an electric mixer or a good arm workout.
Mix in 1 large egg, 1 teaspoon vanilla extract, 1 tablespoon finely grated key lime zest and 2 tablespoons fresh key lime juice until combined.
Add the dry ingredients to the wet in two additions and stir just until no streaks of flour remain; don’t overmix or the cookies will get tough.
Chill the dough for at least 30 minutes in the fridge (helps them keep shape and brightens the lime flavor), or up to 2 hours.
Scoop rounded tablespoonfuls (or a small cookie scoop) and roll into balls, place about 2 inches apart on the prepared sheet; if dough is rock hard let it sit 5 minutes to soften.
Bake 10 to 12 minutes until edges are set and centers still look slightly soft; they firm up as they cool, so avoid browning.
Let cookies cool on the sheet 4 to 5 minutes, then roll each warm cookie in about 1 cup powdered sugar to coat. Transfer to a wire rack to cool completely and roll again for a thicker snowy cloak.
Store in an airtight container at room temp for up to 3 days, or freeze for longer; pro tip: more zest equals more punch, so add a little extra if you want a brighter lime kick.

Notes

Below you’ll find my best estimate of this recipe’s nutrition facts. Treat the numbers as a guide rather than a rule—great food should nourish both body and spirit. Figures are approximate, and the website owner assumes no liability for any inaccuracies in this recipe.