Preheat oven to 350°F (175°C). Grease and flour two 9-inch cake pans.
Mix dry ingredients: Whisk flour, baking powder, and salt. Set aside.
Cream butter & sugar: Beat butter and sugar until fluffy. Add eggs one at a time, then vanilla.
Combine wet & dry: Alternate adding dry mix and milk to the batter. Fold in mashed raspberries.
Bake for 30–35 mins until a toothpick comes out clean. Cool completely.
Make raspberry filling: Simmer raspberries, sugar, cornstarch, and water until thickened. Cool.
Make frosting: Beat butter, melted white chocolate, powdered sugar, heavy cream, and vanilla until smooth.
Assemble: Spread raspberry filling between cake layers. Frost with white chocolate frosting.
Decorate: Garnish with fresh raspberries and white chocolate shavings.
