Step 1

Preheat oven to 350 degrees.

Step 2

Using a food processor, mix graham crackers and vanilla wafers, pulsing until they reach fine crumbs. Add in melted butter, salt, vanilla extract, and brown sugar, and mix until combined.

Step 3

Pour the crust into a deep dish 9” or 10” pie plate and press into an even layer.

Step 4

Bake for 10 minutes.

Step 5

Whisk granulated sugar, salt, and cornstarch together in a medium sized saucepan. Set aside.

Step 6

Whisk egg yolks, half & half, and key lime juice together in a separate bowl.

Step 7

Over medium heat, whisk the liquid into the saucepan.

Step 8

Bring the mixture to a boil over medium heat, whisking constantly.

Step 9

Once boiling, cook the mixture for 30 seconds to 1 minute (whisking constantly), until the custard has thickened and coats the back of a spoon (mine took roughly 45 seconds, then it was done).

Step 10

Remove from heat and add unsalted butter, key lime zest, and vanilla extract. Whisk until combined.

Step 11

Transfer the custard to a bowl. Place the bowl with the custard in a larger bowl that has been filled with ice. Whisk the custard to cool it down.* (See notes for an alternative method.)

Step 12

Once cool, pour the custard over the crust and smooth it into an even layer. Set aside.

Step 13

Whisk heavy whipping cream with a standing mixer or a hand mixer (using the whisk attachments) until soft peaks form. Add in powdered sugar and vanilla extract. Continue whisking until stiff peaks form, or it has reached your desired whipped cream consistency.

Step 14

Spread the whipped cream on top of the custard (you can also pipe the whipped cream on top).

Step 15

Sprinkle extra key lime zest, if desired.

Step 16

Cover and refrigerate at least 3-4 hours before serving (I suggest refrigerating overnight if possible—the pie is more flavorful as it sits).

Step 17

Slice and serve.