Preheat oven to 350°F. Line a muffin pan with cupcake liners. Set aside.
In a medium bowl, whisk together flour, baking powder, and salt.
In a large bowl, beat the butter, vanilla, and sugar until light and fluffy.
Add in the eggs, one at a time, beating well after each addition. Mix in sour cream and milk.
Fold the dry ingredients into the batter, mixing just until combined.
Using a rubber spatula, gently fold the raspberries, stirring just until combined.
Fill the cupcake liners about 3/4 of the way. Bake for 20-22 minutes or until a toothpick inserted into the center comes out clean. Allow to cool completely on a wire rack.
Make the buttercream by mixing together the butter and powdered sugar until light and fluffy. Add the melted white chocolate and mix until smooth.
Using a small knife or a piping nozzle, cut out the centers of the cupcakes. Fill in the centers with raspberry jam.
Pipe the buttercream onto cupcakes. Decorate each cupcake with a square of white chocolate, a fresh raspberry, rosemary, and sprinkles.
Notes
The nutrition facts stated here do not include any garnishes.
Be sure butter, milk, eggs, and sour cream come to room temp before beginning.
Store leftover cupcakes in an air-tight container in the refrigerator for up to 5 days.