Step 1

FOR THE CAKE: Using serrated knife, split cakes horizontally 1 inch from bottom. Using your fingers, crumble tops into small crumbs; set crumbs aside in airtight container. Set 1 remaining cake round in 9-inch springform pan; reserve second cake round.

Step 2

FOR THE FROSTING: Using stand mixer fitted with paddle, beat confectioners’ sugar and butter on medium-high speed until fluffy, about 2 minutes. Cut 8 ounces cream cheese into 4 pieces and add 1 piece at a time, continuing to beat until incorporated, about 30 seconds. Beat in vanilla and salt. Refrigerate frosting until ready to use.

Step 3

FOR THE FILLING: Sprinkle gelatin over 1/2 cup heavy cream in small saucepan and let sit until gelatin softens, about 5 minutes. Cook mixture over low heat until edges are just bubbling. Add white chocolate and continue to cook, stirring constantly, until just melted and smooth. Set aside to cool slightly, about 15 minutes. Using clean stand mixer fitted with whisk, whip remaining 1 cup heavy cream on medium-high speed to soft peaks, 1 to 2 minutes; transfer to medium bowl and set aside. Using now-empty stand mixer fitted with paddle, beat remaining 1 pound cream cheese and granulated sugar on medium-high speed until light and fluffy, 2 to 3 minutes. Reduce speed to medium-low, add white chocolate mixture, and mix until just combined, scraping down sides of bowl as needed. Using rubber spatula, gently fold in whipped cream until combined.

Step 4

TO ASSEMBLE: Spread filling over cake in pan and smooth into even layer. Place remaining cake round, cut side down, on top. Cover with plastic wrap and refrigerate until set, about 6 hours. Run thin knife between cake and sides of pan; remove sides of pan. Transfer cake to cake stand or plate. Spread frosting in even layer over top and sides of cake. Gently press reserved cake crumbs onto sides of cake. Place mound of chocolate curls in center of cake. Serve.