Preheat your oven to 350°F (175°C) and line a cupcake pan with paper liners.

Sift together flour, cocoa powder, baking powder, baking soda, salt, and espresso powder in a bowl.

Beat butter and sugar together with an electric mixer until light and fluffy, about 1-2 minutes.

Mix in egg, egg yolk, and vanilla until pale and well combined, about 1 minute.

Stir in milk and sour cream until smooth.

Fold the dry ingredients into the wet mixture until just combined.

Spoon batter into liners, filling them about ¾ full, and bake for 17-20 minutes until a toothpick comes out clean.

Cool cupcakes in the pan for 10 minutes before transferring to a wire rack.

Heat heavy cream in a pan until simmering, pour over chocolate, let sit for 2 minutes, then stir in raspberry preserves.

Beat softened butter for frosting until fluffy, then gradually add powdered sugar and freeze-dried raspberries.

Once cooled, remove a small portion from the center of each cupcake, fill with ganache, then pipe on frosting.