First, make the Lime Curd by combining sugar, lime juice, salt, eggs and yolks in a saucepan. Whisk to combine thoroughly and place over medium heat. Stir constantly until mixture thickens like pudding. Remove from heat and whisk in butter a couple small pieces at a time. Strain if you wish (I usually don't) then add lime zest and vanilla, stir well, then transfer to a jar, place in fridge, and allow to cool completely.

Next, make the graham cracker crumble by pulsing graham crackers, sugar, salt, and butter in the food processor until you have a fine crumb. Alternatively you can do this in a large zip top bag by crushing and squishing everything together either with your hands or a rolling pin.

Place this mixture into a skillet over medium heat and toast, stirring very frequently, until the crumbs become toasty and fragrant. This should take about 5 minutes. Remove skillet from heat and allow crumbs to cool. Store in an airtight container or small zip-top bag until ready to use. 

At this point place a large glass or metal baking dish in the freezer. I use a large glass pyrex. It's nice to have it cold before adding the ice cream mixture to it.

When the curd and crumbs are made and completely cooled, move on with the final steps:

In a large bowl combine sweetened condensed milk, lime juice, vanilla, and zest and whisk to combine. In another large bowl, whisk heavy cream until stiff peaks form (you're just making whipped cream here). I use a hand mixer for this but you could whisk by hand or use a stand mixer with a whisk attachment as well. 

Next, add about 1/2 the whipped cream to the sweetened condensed milk mixture and fold and stir together. Add the rest of the whipped cream and fold to combine. Try to fold gently but don't get too fussy about it. 

See photos in post for reference on the layering process

In your chilled baking dish, add a thin layer of graham cracker crumbs evenly to the bottom- about 1/3 of your mixture.

Next add 1/3 of the ice cream mixture followed by 4-5 blobs of lime curd

repeat this layering until all ingredients are used up. You'll want to end with the final 1/3 of the cream mixture followed by a few blobs of curd. This makes the prettiest presentation, but don't worry too much - it will be so delicious no matter what order you end in!

Using a butter knife or chopstick, swirl the ice cream together, making sure to reach all the way to the bottom so you get some good swirls of all ingredients throughout. 

cover with plastic wrap and place in the freezer for 6-8 hours.