Preheat your oven to 350F. Line a 12 cup muffin tin with cupcake liners.

Melt the unsweetened chocolate in a microwave or double boiler. Combine the melted chocolate with the cocoa powder and hot water and mix until combined. Set aside.

In a stand mixer fitted with a paddle attachment, cream together the butter and brown sugar until well combined and pale yellow. Add the eggs one at a time on medium speed. Stop the mixer to give the bowl a good scrape before continuing on.

Add the chocolate mixture and mix on medium speed until combined. Scrape the bottom of the bowl with a rubber spatula again to ensure it's well mixed.

Combine the dries and add half it to the mixer on medium low speed. Add the sour cream and mix. Add the rest of the dries and mix just until combined.

Bake the cupcakes at 350F for 20 minutes or until it springs back to the touch or a toothpick comes out clean when inserted. Let it cool to room temperature before pipping on the grey stuff.