Crust
5 tablespoons butter, melted
2 cups plus 2 tablespoons granulated sugar
1 cup graham cracker crumbs

In a mixing bowl, combine the melted butter, 2 tablespoons of the sugar and graham cracker crumbs. Mix well. Press the crust firmly over the bottom of a 9-inch spring-form pan. Set aside.

Filling
1 envelope unflavored gelatine
3/4 cup Key lime juice
4 eggs (at room temperature)
2 egg yolks (at room temperature)
2 tablespoons grated Key lime zest
16 ounces cream cheese (at room temperature)
2 egg whites (at room temperature)
Pinch of salt
2 cups sweetened whipped cream

In a saucepan dissolve gelatine in the Key lime juice for about 5 minutes. Add 1 1/4 cups of the sugar, eggs, egg yolks and lime zest. Mix well. Cook over medium heat until the mixture thickens and is pudding-like, about 7 to 8 minutes. Remove from the heat.

In the bowl of an electric mixer fitted with a paddle attachment, beat the cream cheese until smooth. With the mixer running, add the lime mixture slowly and beat until smooth. Remove the mixture and turn into a bowl and cool completely. Cover with plastic wrap and refrigerate until chilled, stirring every 10 minutes.

In the bowl of an electric mixer with a whip attachment, place the egg whites and remaining 1/4 cup sugar. Whip on medium high until stiff peaks form. Remove the lime and cheese mixture from the refrigerator. Fold the egg whites into the lime mixture and blend thoroughly. Pour the mixture into the prepared crust. Cover with plastic wrap and refrigerate until set, about 4 hours.

Remove from the refrigerator. Run a sharp knife along the sides of the pan and remove the spring-form. Spread the whipped cream evenly over the top of the cake.

Candied Zest
1 cup simple syrup (1 cup granulated sugar and
    1 cup water heated until sugar dissolves)
Rind of 2 limes, julienned
12 sprigs fresh mint

In a saucepan over medium heat, combine simple syrup and lime zest. Bring the liquid to a simmer and cook for 3 to 4 minutes. Remove the zest from the liquid and cool on parchment paper.

Cut the cake into individual servings. Garnish with candied lime zest and mint sprigs.