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

In a large mixing bowl, sift together the all-purpose flour, Dutch process cocoa powder, baking powder, baking soda, salt, and optional espresso powder.

Using a hand mixer, beat the softened unsalted butter and granulated sugar for about 1-2 minutes until light and fluffy.

Add the egg, egg yolk, and vanilla extract, mixing until pale and fluffy.

Gradually mix in the whole milk and sour cream until well-blended.

Slowly add the sifted dry ingredients to the wet ingredients, mixing just until combined.

Fill each lined cupcake well about ¾ full with batter and bake for 17-20 minutes or until a toothpick comes out clean.

Allow cupcakes to cool in the pan for 10 minutes, then transfer to a wire rack to cool completely.

In a saucepan, heat the heavy cream until steaming, then pour it over the chopped semi-sweet chocolate.

Mix in raspberry preserves into the cooled ganache until smooth.

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

Remove the center of each cooled cupcake, fill with ganache, and top with raspberry buttercream.