Place the finely chopped 8 ounces semisweet or bittersweet chocolate in a medium heatproof bowl.
8 ounces semisweet or bittersweet chocolate
In a small saucepan, heat the 1 cup heavy cream over medium heat until it just begins to simmer. Do not let it boil.
1 cup heavy cream
Pour the hot cream over the chopped chocolate and let it sit for about 2-3 minutes to melt the chocolate. After a few minutes, gently whisk the mixture until the chocolate is fully melted and the ganache is smooth and glossy. Stir in the 1 tsp vanilla extract.
1 tsp vanilla extract
Allow the ganache to cool at room temperature for about 10-15 minutes, then transfer it to the refrigerator to chill for about 1 hour, or until it thickens but is still soft enough to whip.
Preheat your oven to 350°F (175°C) and line a cupcake tin with paper liners.
In a medium bowl, whisk together the 1 cup cake flour, 1/2 cup cocoa powder, 1 1/2 tsp baking powder, and 1 tsp salt. Set aside.
1 cup cake flour, 1/2 cup cocoa powder, 1 1/2 tsp baking powder, 1 tsp salt
In a large bowl, beat the softened 1/2 cup salted butter and 1 cup granulated sugar together until light and fluffy, about 3-4 minutes.
1/2 cup salted butter , 1 cup granulated sugar
Add the 2 eggs one at a time, beating well after each addition. Mix in the 1 tsp vanilla extract.
2 eggs, 1 tsp vanilla extract
Gradually add the dry ingredients to the butter mixture, alternating with the 3/4 cup whole milk, beginning and ending with the dry ingredients. Mix until just combined.
3/4 cup whole milk
Divide the batter evenly among the cupcake liners, filling each about 2/3 full.
Bake in the preheated oven for 18-22 minutes, or until a toothpick inserted into the center comes out clean.
Let the cupcakes cool in the tin for 5 minutes, then transfer them to a wire rack to cool completely.
Using a hand mixer or a stand mixer with the whisk attachment, whip the ganache on medium-high speed until it becomes light, fluffy, and holds soft peaks, about 2-4 minutes. Be careful not to overwhip, as the ganache can become grainy.
Generously frost each cupcake with the prepared chocolate ganache. Use an offset spatula to smooth the edges into a dome shape.
Roll each cupcake in1/2 cup cocoa powder, tapping to remove the excess.
1/2 cup cocoa powder
Top each cupcake with a drizzle of melted chocolate.