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key lime pie ice cream

The BEST Key Lime Pie Ice Cream Recipe

Meagan Glemboski
This recipe is time-consuming, but the end result is nothing short of ABSOLUTE PERFECTION!
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Prep Time 2 hours
Cook Time 6 hours
Course Dessert
Cuisine American
Servings 6

Equipment

  • 1 Ice Cream Maker

Ingredients
  

Toasted Sugar

  • 9 cups Granulated Sugar For Toasting

Toasted Sugar Browned Butter Scotch Shortbread

  • 1 cup Unsalted Butter (2 Sticks)
  • ½ cup Toasted Sugar
  • 1 tsp Pure Vanilla Extract
  • 2 cups Unbleached All-Purpose Flour
  • ¼ cup Cornstarch
  • ⅛ tsp Kosher Salt
  • Sanding Sugar (Optional)

Tangy Key Lime Curd

  • 5 Egg Yolks
  • ¾ cup Granulated Sugar
  • 2-3 tsp Key Lime Zest
  • ½ cup Key Lime Juice
  • ⅛ tsp Kosher Salt
  • 4 tbsp Unsalted Butter (Cubed)

BEST Key Lime Pie Ice Cream

  • 1 cup Whole Milk
  • 2 cup Heavy Whipping Cream
  • ⅓ cup Toasted Sugar
  • ½ tsp Kosher Salt
  • 1 cup Tangy Key Lime Curd
  • Scotch Shortbread (Add as much or as little as you like! Entirely up to your preference.)

Instructions
 

Toasted Sugar

  • Toast the Sugar!
  • The recommendation from Serious Eats is to toast about 4 lbs (or 9 cups) of granulated sugar in a glass baking dish at 300F for roughly 5 hours. That’s assuming you have a convection oven; otherwise, as I mentioned, this may be a trial-and-error pursuit that takes longer. The flavor pay off is absolutely worth it, so here are my troubleshooting methods for making this work:
    9 cups Granulated Sugar For Toasting
  • Temperature adjustment: Using my oven thermometer, it was obvious pretty early on that my oven heats unevenly. Ultimately, I settled on actually bumping the temp up to about 315-325F.
  • Spread out the sugar between two glass dishes to thin it/toast it faster.
  • I don’t recommend having the baking rack lower than the middle of the oven. Too close to the heating coils, it’s going to liquefy before you know it. It happens fast if it gets too hot, too quickly.
  • Sometimes the kitchen lighting can make it difficult to tell if you’re making any progress with sugar-toasting; it can help if you hold a spoon of untoasted sugar next to the dish of sugar from the oven to see any difference.
  • After the first hour that the sugar has been in the oven, gently stir the sugar in the dish. This is to help circulate the warmer sugar from the edges and bottom of the dish and the cooler sugar from the top and middle of the dish so that it can toast evenly. It also helps release steam and moisture from the sugar to help prevent it from actually liquefying. From this point forward, you’ll want to stir the sugar like so every 30 minutes until it reaches the desired color and level of toasting.
  • The longer the sugar toasts, it will eventually begin to look more like golden, light brown sugar. It also tends to clump as moisture is released, and you can end up with hard, crystallized clumps of sugar. This is fine, as once it’s cooled, you can blitz it in a food processor. I actually use a Ninja blender cup and pulse it intermittently about 8 times or so. If you blend it instead of pulsing it, it will be more like a powdered sugar consistency (but still super yummy).
  • Make sure to store your toasted sugar in an airtight container. I like to use something like this or a mason jar.

Toasted Sugar Browned Butter Scotch Shortbread

  • Bake the Shortbread!
  • Start by browning the butter. In a skillet over medium to med-high heat, melt the butter down, and stir it gently, but constantly, to ensure that it doesn’t burn. Watch carefully, since as the butter darkens, it can quickly cross the line from browned to burnt if you aren’t paying attention. The fat solids from the butter will separate and start from a pale yellow, shift to gold, and finally get to a nice, dark brown and smell nutty. Remove from heat, allow to cool for a few minutes, pour into a stand-mixer stainless steel mixing bowl and finish cooling to room temperature. The brown butter, as it cools, will become opaque and solidify. This can take a couple of hours before it’s completely cool and solid.
    1 cup Unsalted Butter (2 Sticks)
  • Beat the butter with a paddle attachment at medium speed for a few moments. It’ll already be fairly creamy and soft. Add in your toasted sugar and beat well for 2-3 minutes. The smell will be AMAZING, and the mixture will be so light and fluffy. Stir in the pure vanilla extract.
    ½ cup Toasted Sugar, 1 tsp Pure Vanilla Extract
  • In a separate bowl, whisk together flour, cornstarch, and salt. Slowly add this dry ingredient mix into the butter mixture and beat at low speed. It will be a soft, almost airy, light dough. (I attempted to knead this dough a few times on a floured counter, but it didn’t feel necessary–the consistency just felt unreal and perfect as it was).
    2 cups Unbleached All-Purpose Flour, ¼ cup Cornstarch, ⅛ tsp Kosher Salt
  • Press dough into an ungreased, parchment-paper lined pan. Since I doubled the recipe, I used a large cookie sheet; however, for a single batch, you should be able to use a 9x9 pan. Press out the dough evenly till it reaches all corners and edges and is generally the same thickness throughout. Prick the dough with a fork at regular 1” intervals (this helps to prevent cracking/bubbling during the baking process). Cover with plastic wrap and chill in the fridge for at least 2 hours (as soft as the dough feels, chilling in the fridge will firm the fat from the butter and harden it back up so that it will be more crispy and mix into the ice cream better after baking).
  • Preheat oven to 325F. At this point, if desired, you can sprinkle the shortbread dough with sanding sugar before baking. Bake for 35 minutes, until it’s lightly golden at the edges. I actually don’t mind even letting it bake a couple minutes longer, within reason, to allow it to dry out just a little more. Crunchier texture for the ice cream! Allow to cool completely; I store it back in the fridge, covered, until I’m ready to add it into the ice cream base.
    Sanding Sugar (Optional)

Tangy Key Lime Curd

  • Cook the Curd!
  • I recommend prepping your key lime juice and zest before putting the curd together. Key limes are tiny and it takes a lot of them and a bit of time to get ½ cup of juice and upwards of 1 T of lime zest, depending on how tangy you like your curd (I like a nice, zingy, citrus bite–and the zest is aesthetically pleasing in the ice cream also). Alternatively, you can use regular limes, but it’s definitely not my preference.
    2-3 tsp Key Lime Zest, ½ cup Key Lime Juice
  • In a heatproof bowl, whisk egg yolks, sugar, key lime juice and zest, and salt until well combined.
    5 Egg Yolks, ¾ cup Granulated Sugar, ⅛ tsp Kosher Salt
  • I don’t own a double-boiler, so I just use a saucepan over medium heat, wait for the water to get hot, then place the heatproof bowl over the saucepan. Whisk the key lime mixture constantly until thickened. You’ll know it’s thick enough when it coats the back of a spoon.
  • Remove the curd from the heat. Drop in the cubes of butter and stir the mixture until the butter is completely melted. Let it cool to room temperature. Cover with plastic wrap, but let the plastic wrap actually touch the surface of the curd. This will help prevent any skin from forming as it further cools and sets up in the refrigerator.
    4 tbsp Unsalted Butter (Cubed)

Best Key Lime Pie Icecream

  • Churn Some Ice Cream!
  • For the ice cream base, mix milk, heavy whipping cream, toasted sugar, and salt in a medium saucepan and bring to a simmer over medium to med-high heat. You want to make sure that the sugar is fully dissolved, but I like to make sure that it really gets hot and simmers enough for a light “skin” to start to form on the surface. Once it gets to this point, it has a nostalgic flavor that smacks of homemade stovetop vanilla pudding that is absolutely scrumptious. Remove from heat.
    1 cup Whole Milk, 2 cup Heavy Whipping Cream, ⅓ cup Toasted Sugar, ½ tsp Kosher Salt
  • Let the saucepan cool over a bowl of ice water, and stir the ice cream base from time to time. Once it has cooled (room temp to still slightly warm), mix in your tangy key lime curd until smooth and well incorporated.
    1 cup Tangy Key Lime Curd
  • Pour ice cream mixture into your ice cream maker and churn/process according to the manufacturer’s instructions. With my electric old-fashioned ice cream maker, I churn it for roughly 30 minutes.
  • While it churns, break up the shortbread by putting it in a ziploc bag, pushing the air out before sealing, and using a rolling pin or meat tenderizer until it’s in ideal form. I like a decent mix of “sand” and “chunks” (I couldn’t think of a more appetizing description) of shortbread crumbles. Once the 30 minutes or so is up, add in your mix-ins to the ice cream and allow it to churn for about 5-10 minutes longer. You may want to add in the shortbread gradually to ensure that it doesn’t “gum up” the churning paddle. If it does, just mix it in with a spatula before replacing the paddle.
    Scotch Shortbread (Add as much or as little as you like! Entirely up to your preference.)
  • Transfer the ice cream to an airtight container, like this, and freeze until firm, generally at least 4 hours. Bear in mind that when the ice cream freezes, it will expand in whatever container you store it in, so give it a little breathing room.
  • ENJOY the BEST Key Lime Pie Ice Cream EVER!
    key lime pie ice cream
Keyword curd, ice cream,, key lime pie, pie, shortbread, toasted sugar