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

In a small bowl, sift together all the dry ingredients: flour, cocoa powder, baking powder, baking soda, salt, and espresso powder.

Cream together softened unsalted butter and granulated sugar until light and fluffy, about 1-2 minutes.

Add in one whole egg, an additional egg yolk, and vanilla extract, mixing until pale and fluffy.

Pour in the whole milk and sour cream, mixing until just incorporated.

Gradually add the sifted dry ingredients to the wet mixture, stirring gently until just combined.

Spoon the batter into cupcake liners, filling them about ¾ full. Bake for 17-20 minutes until a toothpick comes out clean. Cool in the pan for 10 minutes.

Heat heavy cream until steaming. Pour it over chopped chocolate and let sit for 2 minutes before stirring until smooth. Mix in raspberry preserves.

Beat softened unsalted butter with a pinch of salt until fluffy. Gradually add powdered sugar and mix in crushed freeze-dried raspberries.

Core the centers of the cooled cupcakes and fill with ganache. Pipe raspberry buttercream on top.

Garnish with fresh raspberries or a dusting of cocoa powder if desired.