Preheat the oven to 350°F (175°C) and grease and flour three 8-inch cake pans.

In a medium bowl, whisk together the flour, baking powder, and salt.

In a large mixing bowl, cream the butter and sugar until light and fluffy. Add the eggs one at a time, followed by the vanilla and melted white chocolate.

Gradually add the flour mixture to the butter mixture, alternating with the milk. Mix until just combined.

Divide the batter among the prepared pans and bake for 25-30 minutes or until a toothpick comes out clean.

For the filling, combine raspberries, sugar, and lemon juice in a saucepan over medium heat. Mash raspberries and add cornstarch mixed with water once bubbling. Stir until thickened then cool.

For the frosting, beat softened butter and gradually add powdered sugar. Stir in cooled melted white chocolate and enough milk for desired consistency.

Once cooled, level the cake layers, frost between layers with frosting and raspberry filling, then frost the entire cake.

Chill the cake for at least 30 minutes before decorating with fresh raspberries, white chocolate curls, and mint leaves.