In a microwave-safe bowl, melt white chocolate and butter at 70% power; stir until smooth. Cool.
In a large mixing bowl, beat eggs and sugar until lemon-colored. Beat in melted chocolate mixture and vanilla. Combine flour and salt; beat into egg mixture. Spread into a greased 13-in. x 9-in. x 2-in. baking dish; set aside.
For filling, in a small mixing bowl, beat cream cheese and white chocolate. Beat in the egg, sugar, sour cream and vanilla just until combined. Carefully spread over bottom layer. Cut through filling with a knife to swirl.
Bake at 350° for 40-45 minutes or until a toothpick inserted near the center comes out clean. Cool on a wire rack.
Just before serving, fold whipped topping into white chocolate. Fold in strawberries; spread over dessert. Cut into squares. Refrigerate leftovers. Yield: 15 servings.