Add heavy cream, finely chopped bittersweet chocolate, and confectioner’s sugar to a microwave safe bowl. Heat in the microwave at ½ power in 30 second intervals, stirring between. Continue until chocolate has just melted and whisk until fully melted and smooth. Place in the fridge for 20 minutes ONLY, then remove to the counter. If the ganache is too cold, this may cause your cupcakes to sink and form holes in the center.

Preheat oven to 350°F.

In a standard cupcake or muffin tin, place liners and set aside

Combine finely chopped chocolate, cocoa powder and espresso powder in a large bowl. Heat milk in a saucepan until just warm (alternatively, you can microwave the milk at ½ power in 30 second intervals until warm), then pour milk over the top of the chocolate mixture and let it sit for 1 minute. Whisk until smooth and place in the fridge to cool and prepare your remaining ingredients.

In another bowl, combine flour, sugar, salt, and baking soda.

Remove chocolate espresso mixture from the fridge and add your oil, vinegar, eggs, egg yolk, and vanilla. Whisk to fully combine. Add the flour mixture a little bit at a time, and whisk to incorporate completely.

Pour your batter into your cupcake liners. Add about 1 teaspoon of the ganache to the center of each cup on top of the batter. The ganache will sink into the batter as the cupcakes bake.

Bake cupcakes for 16-18 minutes on the center rack. You want to bake these until just firm. Once done, remove the cupcakes from the oven and allow them to cool for about 10-15 minutes in the tray before removing the cupcakes, then allow the cupcakes to cool completely before frosting them. As the cupcakes cool, the dome on top will flatten out, this is normal.

In a stand mixer, add butter and mix on high until fluffy.

Slowly add confectioners sugar and mix until combined.

Slowly drizzle syrup in a little at a time and allow it to incorporate completely before adding more. Next add the whiskey and continue to mix to incorporate.

Add remaining ingredients and mix until smooth and desired consistency. Add more confectioners sugar for a thicker consistency as needed.

Add filling to a piping bag and evenly pipe onto cupcakes. Drizzle with extra maple syrup if desired.