Incredibly soft, tender and moist chocolate cupcakes with rich chocolate flavour topped with a smooth, not-too-sweet dark chocolate buttercream and dark chocolate glaze.
Preheat your oven to 350°F. Line 18 cups from two standard 12-cup muffin pans with paper liners.
In a medium bowl, sift together flour, cocoa powder, baking powder, baking soda and salt; whisk to blend evenly.
In a large bowl, beat butter on medium-high speed until creamy using an electric hand mixer, about 10 seconds. Add sugar and beat until light and fluffy, about 2 minutes. Add melted, cooled chocolate and beat on medium speed until well combined. Beat in eggs, one at a time, mixing until each one is well incorporated. Then, beat on high speed for 10 seconds to whip the eggs and make the batter a bit fluffy. Add sour cream and vanilla and beat on high speed until the batter is voluminous, 20-30 seconds.
With mixer on medium-low speed, add one-third of flour mixture. Once mostly blended, add half of the milk and beat until almost completely incorporated. Repeat this step by adding half of the remaining flour mixture followed by the rest of the milk. Do not beat more than 15 seconds between additions. Finally, add the last of the flour mixture and beat until well incorporated. Scrape down the sides and bottom of the bowl and then beat on medium-high speed for 5 seconds. Do not over-beat to ensure a tender crumb.
Divide batter evenly among lined muffin cups filling them about two-thirds full. Bake until a toothpick inserted into the center of the cakes comes out clean, 16-20 minutes. Transfer cakes to a wire rack to cool completely. R
To make the frosting, combine soft butter with 1 ½ cups of icing sugar and 2 tablespoon of cream. Beat until smooth and creamy. Beat in vanilla and salt. Add cooled melted chocolate and mix on low until combined, then beat in remaining 2 tablespoon of cream. Add the last ½ cup of icing sugar and beat until smooth. Do not over beat or the mixture will become too stiff and grainy as the chocolate cools, and you won’t be able to spread it.
To make the glaze, combine chocolate, water and corn syrup in a small saucepan over low heat and whisk until the chocolate is completely melted, smooth and glossy. Remove from heat and let cool completely.
To assemble the cupcakes, spread a generous amount of frosting over each cupcake using an offset spatula or pipe it on using a piping bag, then drizzle with cooled chocolate glaze.