• Preheat oven to 350°F.
• Line standard muffin cups with paper liners, or grease with butter and dust with flour (you'll have enough batter for 18 to 20 cupcakes).

Make the Cupcakes

• Place the cocoa powder in a bowl and slowly whisk in the boiling water until fully incorporated.
  ¾ cup natural cocoa powder, ⅔ cup boiling water
• Let cool slightly, then whisk in the buttermilk.
  1 cup buttermilk
• In a different bowl, whisk together the flour, baking soda, and salt.
  1¾ cups all-purpose flour, 1½ teaspoon baking soda, ½ teaspoon salt
• In the bowl of a mixer fitted with the paddle attachment, beat (also known as "creaming") the butter and sugars on medium until combined and fluffy.
  ¾ cup unsalted butter, 1 cup sugar, ½ cup brown sugar
• One at a time, add the eggs, beating well after each addition. Add the vanilla with the final egg.
  3 large eggs, 2 teaspoon vanilla extract
• Reduce the speed to low and add the flour mixture in 3 additions, alternating with the cocoa-buttermilk mixture in 2 additions, starting and ending with the dry ingredients. Beat until just combined.
• Divide the batter among the prepared muffin cups, filling them about three-quarters way up.
• Bake the cupcakes until they are puffed and slightly springy to the touch and an inserted toothpick comes out clean. About 20 minutes.
• Let cool slightly, then remove the cupcakes from the pan and cool completely on wire racks.

Make the Filling and Fill the Cupcakes

• Place the softened butter in the bowl of a mixer and add the sugar. Using the paddle attachment, beat on medium speed until lightened.
  6 tablespoon unsalted butter, 1½ cup confectioners' sugar
• Add the marshmallow cream (fluff), vanilla, and cream, beating until light and fluffy. Set aside.
  1 cup marshmallow creme "fluff", 1 teaspoon pure vanilla extract, 2 tablespoon heavy cream
• Using a small sharp knife, create a hole in the top of each cupcake about 1½ inches round and 1 inch deep.
• Fill each cavity with marshmallow filling.

Make the Frosting and Top the Cupcakes

• In a large bowl with an electric mixer (or use your stand mixer), beat together the softened cream cheese, butter (1 stick softened), and vanilla extract until light and fluffy.
  8 oz cream cheese, ½ cup unsalted butter, 2 teaspoon vanilla extract
• Beat in the cocoa powder until combined. Begin adding the confectioners' sugar until a frosting consistency is reached, usually about 3 cups.
  ½ cup unsweetened cocoa powder, 3 to 4 cups confectioners' sugar
• Use an offset spatula or a pastry bag (with a tip) to frost the cupcakes. Sprinkle with cupcake gems, if using.
  gold cupcake gems