Preheat your oven to 350°F (175°C) and line a cupcake tin with liners. In a large mixing bowl, sift together the all-purpose flour, granulated sugar, Dutch-processed cocoa powder, baking soda, baking powder, and kosher salt. In a separate bowl, whisk together the egg, sour cream, vegetable oil, and vanilla extract until smooth. Gradually pour the wet mixture into the dry ingredients, stirring until just combined. Add the hot coffee and mix until you have a silky batter.

Fill each cupcake liner halfway with the prepared chocolate batter, which should be rich and glossy. Place the tin in the preheated oven and bake for 13-15 minutes, watching for the cupcakes to rise and domed in the center. To test for doneness, insert a toothpick into the center; it should come out clean. Remove the tin from the oven and allow the cupcakes to cool completely on a wire rack.

While the cupcakes are cooling, prepare the chocolate ganache filling. In a saucepan, heat the heavy whipping cream over medium heat until it just begins to simmer. Remove it from the heat and pour it over the chopped semi-sweet chocolate in a heatproof bowl. Let it stand for 5 minutes, then stir gently until smooth and shiny. Allow the ganache to chill in the refrigerator for about 30 minutes until it thickens to a spreadable consistency.

Next, prepare the luscious strawberry swiss meringue buttercream. Start by placing the egg whites and granulated sugar in a heatproof bowl over a pot of simmering water. Whisk constantly until the mixture is warm to the touch and the sugar dissolves, about 3-5 minutes. Remove from the heat, then beat with a stand mixer on high speed until stiff peaks form and the mixture cools. Gradually add room temperature unsalted butter, mixing until creamy, and then blend in the powdered freeze-dried strawberries and vanilla extract.

Take each completely cooled cupcake and use a small knife or cupcake corer to remove a small section from the center. Fill each cupcake with the chilled chocolate ganache, filling until it reaches the top of the cupcake.

Using a piping bag fitted with a decorative tip, swirl the strawberry buttercream on top of each ganache-filled cupcake. Let the buttercream create a beautiful, generous crown over each cupcake.

Once frosted, your Chocolate Strawberry Cupcakes with Chocolate Ganache Filling are ready to be enjoyed! Allow the cupcakes to sit at room temperature for a bit before serving for the best flavor and texture.