I have a soft spot in my heart for diner-style pie: sour cherry with the insides kinda congealed, apple pie with whipped cream that comes out of a canister, and most of all, key lime pie. Admittedly though, no one likes key lime pie as much as my cousin Jen, which is why last year for her birthday she insisted that be her “cake” (she really doesn’t like cake, what can you do?). “No problem!” I said. Well, it wasn’t a problem until I realized I didn’t actually have a recipe. But then I realized, wait, I make recipes. I can do this. I DO do this*.
So, I made the pie, recipe-less, with only the great bodegas of New York City to supply me, and guess what? It was the best key lime pie I’d ever had, and everyone who tried it that night seemed to agree (although we had been drinking a bit). We think you will, too. Here's how to do it:
No need to use a food processor for this; graham crackers crumble perfectly in one's hands. I like a little texture variation to my crust (some sandier crumbs, a few larger pieces), which is generally obliterated when you use a machine. When mixing it, it’s important the crumbs are all evenly coated in the butter and coconut oil, so they stay together once baked (fat is the glue that binds).
Parbaking the crust gives you an extra crunchy layer, which is a great, necessary pie texture.
The coconut oil makes an appearance because first I actually ran out of butter, but once I thought about it, it made total sense. It acts just like butter but with a better, nuttier flavor. You know that song about putting the lime in the coconut? Well, I guess I literally just put the lime (custard) in the coconut (crust). Ha! Ah, that’s rich. Okay, stay with me.
If you’re not a great appreciator of citrus in all it’s bitter, sweet and sour glory, you may find this filling a bit on the tart side (especially if you’re using real key limes), but for me, its perfect. I have an aversion to very sweet things, and I swear I could** take down this whole pie, no problem.
The trick to the filling is to beat the sweetened condensed milk and yolks together till the mixture lightens in color and gets as much volume as possible (since there are no egg whites, it won’t quite double). The lighter and fluffier your mixture is, the lighter and fluffier your final product will be, so keep beating.
Bake long enough to set the filling—there should be no soufflé-ing, no browning.
When I first made this pie, my new recipe was pretty much born out of necessity—there was literally no heavy cream within a two-mile radius. So I used some full fat yogurt, thinned with milk. I can’t in good conscience say I prefer that to whipped cream, but I do like a touch of yogurt for the acidity and lighter texture. Best of both worlds.