Ensure that all ingredients for the cupcakes are at room temperature. Preheat oven to 170 degree C. Line a 12 cup muffin tin with the cupcake liners

Melt the butter and chocolate. You can either do this using a double boiler over a stove-top or in the microwave. If using a microwave, microwave at 50% in 30 sec intervals stirring each time. It should take about a 1 min or 1 min 30 sec. Set aside to cool.

In a medium sized bow, sift the flour, cocoa powder, baking soda, baking powder and salt

In another large sized bowl, whisk together the eggs, granulated sugar, the light brown sugar and the vanilla essence till smooth. It should take about 3 minutes if using a hand mixer.

To the large bowl with the egg mixture, add the melted chocolate mixture from step 2 and whisk until smooth

Add the flour mixture from step 3 to the chocolate egg mixture in 3 additions alternating with the buttermilk. Ensure that you start and end with the flour mixture. Stir until just combined after each addition

Divide the batter between the 12 liners and bake until just set, for about 18 mts. Take the muffin tin out of the over and cool it over a cooling rack for 10 minutes then take the muffins out from the pan and place on rack to cool completely

While the cupcakes are cooling, make the frosting. Start with sifting the icing sugar and the cocoa powder.

Beat the butter until soft and creamy. (Before beating, ensure that the butter is slightly cool and not completely at room temperature)

To the beaten butter add the vanilla essence and then,add the icing sugar and cream alternately. After each addition, beat only until just combined. The icing will be silky smooth. Pipe onto the cooled cupcakes and decorate with sprinkles