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

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

In a separate mixing bowl, cream the softened unsalted butter and granulated sugar together until light and fluffy.

Blend in one whole egg, the additional egg yolk, and vanilla extract into the creamed mixture until well combined and fluffy.

Gradually add the room temperature whole milk and sour cream to the bowl on low speed, mixing just until combined.

Fold the sifted dry ingredients into the wet batter until just blended, avoiding overmixing.

Spoon the batter into the cupcake liners, filling each about ¾ full and bake for 17-20 minutes.

Make the raspberry ganache by pouring steaming heavy cream over the chopped semi-sweet chocolate and stirring until smooth.

Whip softened unsalted butter in a medium bowl until light and fluffy, then sift in powdered sugar and mix until incorporated.

Add freeze-dried raspberry powder and raspberry preserves to the buttercream and beat until fully combined and airy.

Once cooled, create a small hole in each cupcake and fill with ganache, then top with raspberry buttercream.