Preheat your oven to 350°F (175°C) and line a 12-cup cupcake pan with paper liners.
Sift together flour, cocoa powder, baking powder, baking soda, salt, and espresso powder in a small bowl. Set aside.
Cream together the sugar and softened butter in a large mixing bowl using an electric mixer on high speed until light and fluffy, about 2 minutes.
Add the egg, egg yolk, and vanilla extract, mixing at medium speed until well combined and fluffy, about 2 minutes.
Gradually add the milk and sour cream, mixing on low speed until combined.
Slowly add the dry ingredients to the wet ingredients and mix on low speed until just combined.
Fill each cupcake liner ¾ full with batter. Bake for 18-20 minutes or until a toothpick comes out clean from the center.
Allow the cupcakes to cool in the pan for 10 minutes, then transfer them to a wire rack to cool completely.
Heat the heavy cream in a small saucepan over medium heat, just until it begins to steam.
Place the chopped semi-sweet chocolate in a medium bowl.
Pour the hot cream over the chocolate and let sit for 2 minutes to melt. Stir to combine.
Stir in the raspberry preserves and combine well.
Allow the ganache to cool for 15 minutes, then transfer to a piping bag.
Beat the softened butter and pinch of salt in a large bowl with an electric mixer until smooth, pale, and fluffy, about 5 minutes.
Add the powdered sugar and mix on low speed until fully incorporated.
Crush the freeze-dried raspberries into a fine powder by placing them in a baggie and rolling them with a rolling pin.
Add the crushed raspberries, raspberry preserves, and vanilla to the butter mixture. Beat on low to combine, then on medium-high speed until fluffy.
Transfer the raspberry buttercream into a piping bag fitted with your desired decorative tip.
Once the cupcakes have fully cooled, use a cupcake corer to remove a small portion from the center of each.
Fill each cupcake with raspberry chocolate ganache.
Pipe a generous amount of raspberry buttercream on top of each cupcake. Finish by adding a fresh raspberry on top for decoration.