Preheat the oven to 350°F (175°C) and line a muffin tin with cupcake liners.

In a large mixing bowl, combine flour, sugar, cocoa powder, baking soda, baking powder, and salt.

In another bowl, beat together the softened butter, eggs, vanilla extract, and buttermilk until smooth.

Gradually add the wet ingredients to the dry ingredients and mix until just combined.

Fill each cupcake liner about ⅔ full with batter.

Bake for 18-20 minutes or until a toothpick inserted comes out clean.

Allow cupcakes to cool completely before frosting.

In a saucepan over medium heat, combine brown sugar, heavy cream, and butter.

Cook while stirring until the mixture comes to a boil, then reduce heat and simmer for 5 minutes.

Remove from heat and stir in coconut and pecans.

Let the frosting cool slightly before spreading it on the cooled cupcakes.