1. Prepare the raspberry filling according to the recipe. Allow it to cool completely and chill for at least 30 minutes.

2. Preheat oven to 350°F. Line two 8-inch round cake pans with parchment paper.

3. Sift together flour, baking powder, baking soda, and salt.

4. Beat butter, oil, sugar, and vanilla for 2 minutes until pale and fluffy.

5. Add egg and mix until incorporated. Add egg whites and beat until smooth. Mix in sour cream.

6. Add half of the dry ingredients and mix gently. Add half of the milk and combine. Repeat with remaining flour and milk. Beat on high for 5 seconds to emulsify.

7. Fold in fresh raspberries carefully.

8. Divide batter evenly between pans and bake for 25–30 minutes until a skewer comes out clean. Cool completely.

9. For the frosting, pour hot cream over chopped white chocolate, rest 2 minutes, whisk smooth, add remaining cold cream, and chill at least 2 hours.

10. Whip chilled ganache until thick and fluffy.

11. To assemble, place one cake layer on a plate. Pipe a frosting border, spread raspberry filling inside, add second layer, and frost entire cake. Decorate with raspberries if desired.