In a small bowl, sift together all-purpose flour, Dutch process cocoa powder, baking powder, baking soda, salt, and espresso powder (if using). Set aside.

In a large bowl, cream together softened unsalted butter and granulated sugar using an electric mixer on high speed for 1-2 minutes until fluffy and light in texture.

Add the egg, egg yolk, and vanilla extract to the creamed mixture. Mix on medium speed for 1-2 minutes until light and fluffy.

Pour in the whole milk and sour cream. Mix on low speed just until incorporated.

Gradually add the dry ingredients to the wet mixture on low speed, mixing until just combined.

Preheat the oven to 350°F (175°C). Line a 12-cup muffin pan with cupcake liners and fill each liner about 3/4 full with batter. Bake for 17-20 minutes or until a toothpick inserted comes out clean.

Let the cupcakes cool in the pan for 10 minutes before transferring to a wire rack to cool completely.

Heat heavy cream over medium heat until steaming. Pour over chopped semi-sweet chocolate in a bowl and let sit for 2 minutes. Stir until smooth, then mix in raspberry preserves. Allow ganache to cool for 15 minutes before transferring to a piping bag.

In a large bowl, beat softened unsalted butter with a pinch of salt at high speed for about 5 minutes. Gradually add powdered sugar, followed by ground freeze dried raspberries, raspberry preserves, and vanilla extract. Mix until light and fluffy, then transfer to a piping bag.

Once cupcakes are completely cooled, use a cupcake corer to remove the center of each cupcake. Fill with raspberry chocolate ganache and pipe raspberry buttercream on top. Garnish with a fresh raspberry.