01 - Preheat oven to 350°F. Grease and line three 8-inch round cake pans with parchment paper.
02 - In a medium bowl, whisk together flour, baking powder, and salt until well combined.
03 - In a large bowl, beat butter and sugar until light and fluffy, approximately 3-4 minutes. Add eggs one at a time, mixing thoroughly after each addition.
04 - Mix in melted white chocolate and vanilla extract until fully incorporated into the batter.
05 - On low speed, alternately add flour mixture and milk to the batter, beginning and ending with flour. Mix until just combined, taking care not to overmix.
06 - Divide batter evenly among prepared pans. Bake for 30-35 minutes or until a toothpick inserted into the center comes out clean. Cool cakes in pans for 10 minutes, then turn onto wire racks to cool completely.
07 - In a saucepan, combine raspberries, sugar, lemon juice, and water over medium heat. Bring to a simmer and mash berries thoroughly. Stir in cornstarch and cook for 2-3 minutes until thickened. Transfer to a bowl and cool completely.
08 - Melt white chocolate gently and cool to room temperature. In a large bowl, beat cream cheese and butter until smooth and creamy. Mix in cooled white chocolate and vanilla. Gradually add confectioners' sugar, beating until fluffy and spreadable.
09 - Place one cake layer on a serving plate. Spread with half the raspberry filling. Top with second layer and repeat with remaining filling. Add final cake layer. Frost top and sides evenly with white chocolate cream cheese frosting.
10 - Decorate with fresh raspberries and white chocolate curls as desired. Refrigerate for at least 1 hour before slicing to set the frosting and filling.