Step 1

Preheat oven to 350 degrees. Line one standard size cupcake pan with 12 liners, and an additional pan with four liners, set aside.

Step 2

Whisk together the flour, sugar, cocoa, baking soda, baking powder, and salt in a stand mixer using a low speed until combined.

Step 3

Add eggs, sour cream, buttermilk, warm water, oil, vanilla, and chopped chocolate. Beat on a medium speed until smooth, about a minute.

Step 4

Divide batter evenly between the liners (I prefer using a #20 scoop which is approximately 1/4 cup of batter).

Step 5

Place in the oven and bake for 18-22 minutes or until the tops spring back when touched.

Step 6

Remove from the oven and allow to cool in the pans for 8 minutes. Remove and transfer to wire racks to cool completely.

Step 7

For the frosting: in a large bowl (or the bowl of a stand mixer), beat the butter and cream cheese until light and fluffy, about 2-3 minutes.

Step 8

Carefully add in the cocoa powder, vanilla and salt, beat until combined.

Step 9

With mixing speed on low, gradually add the powdered sugar, one cup at a time. When all of the powdered sugar has been added, beat in heavy cream, then add more if necessary to create a spreadable consistency. The frosting should be on the thicker side.

Step 10

Using a piping bag fitted with an extra large piping tip (see NOTES below for suggestions), pipe onto cooled cupcakes and sprinkle with desired garnish.