Make the Cupcakes

1. Preheat oven to 350°F (175°C) and line a 12-cup cupcake pan with liners.

2. In a large bowl, whisk together flour, sugar, baking powder, and salt.

3. In a separate bowl, mix sour cream, water, oil, egg, and vanilla until well combined.

4. Pour wet ingredients into the dry and stir until just combined.

5. Divide batter evenly between cupcake liners (about ¾ full each).

6. Bake 18–20 minutes or until a toothpick inserted comes out clean.

7. Let cupcakes cool completely on a wire rack.

Prepare Raspberry Buttercream

1. In a large bowl, beat butter until creamy. Add melted white chocolate and mix until smooth.

2. Mix in vanilla, salt, and ¼ cup of raspberry jam.

3. Gradually add powdered sugar and beat until fluffy. Add heavy cream and remaining raspberry jam to desired consistency and color.

4. Transfer to a piping bag.

Fill Cupcakes

1. Once cooled, use a small knife or cupcake corer to remove a center plug from each cupcake.

2. Fill each with raspberry jam using a spoon or piping bag.

Make White Chocolate Ganache

1. In a microwave-safe bowl, melt white chocolate and cream together in 20-second intervals until smooth.

2. Let it cool slightly before drizzling over frosted cupcakes.

Assemble

1. Pipe raspberry buttercream on each filled cupcake.

2. Drizzle with white chocolate ganache.

3. Garnish with fresh raspberries or white chocolate shavings, if desired.