For crust: In a medium bowl, stir together wafer crumbs, butter, and sugar until combined. Press mixture into bottom and up sides of a 10-inch springform pan; refrigerate.
For filling: In a small bowl, stir together lemon juice and gelatin; let stand until softened, about 5 minutes.
In a small saucepan, cook ½ cup cream and white chocolate over low heat, stirring frequently, until mixture is melted and smooth. Stir in gelatin mixture until dissolved, and let cool completely.
In a large bowl, beat cream cheese, 1 cup sugar, and zest with a mixer at medium speed until creamy; add cooled white chocolate mixture and vanilla, beating until combined.
In another large bowl, beat remaining 2 cups cream and remaining ½ cup sugar with a mixer at high speed until soft peaks form. Gently fold whipped cream into cream cheese mixture until well combined. Pour mixture into prepared crust. Cover and freeze for at least 8 hours or overnight.
Remove from freezer, and gently run a knife around sides of pan to release crust; remove sides of pan. Let stand for 10 minutes before slicing. Garnish with white chocolate curls, if desired.
Recipe by Paula Deen Magazine at https://pauladeenmagazine.com/lemon-mousse-cake-recipe/