Step 1

Preheat oven to 325°. Using your hands, crush graham crackers in a large bowl until coarsely ground (you could do this in a food processor if you’d like, just be sure not to process too finely; you want some texture in the larger pieces). Add butter, coconut oil, sugar, and salt and mix until well blended (mixture will resemble wet sand). Transfer to a 9" pie dish. Using your fingers and the underside of a flat measuring cup, press mixture evenly into bottom and up sides of dish. Bake crust, rotating once halfway through, until golden brown on top and crumbs are set, 12–15 minutes. Let cool.

Step 2

Using an electric mixer on medium speed, beat egg yolks and condensed milk in a large bowl until paler and almost doubled in volume, about 5 minutes. Whisk in 2 tsp. lime zest, lime juice, and salt. Pour into cooled crust. Bake pie until filling no longer jiggles and is starting to slightly puff around the edges, 15–20 minutes. Let cool completely.

Step 3

Whip cream and powdered sugar in a large bowl until stiff peaks form. Gently whisk in yogurt and rum, if using. Dollop onto cooled pie, creating dramatic peaks and valleys with an offset spatula or the back of a spoon. Garnish with lime zest.

Step 4

Do Ahead: Crust can be baked 2 days ahead; pie without whipped topping can be made 2 days ahead; pie can be assembled (with topping) 4 hours ahead.