Preheat the oven to 180 C/160 C (fan)/350 F/Gas 4 and line a 12 hole muffin tin with large cupcake cases.
Cream together the butter and sugar until light and fluffy. Add the eggs and beat well.
Sift in the flour, salt, bicarbonate of soda and cocoa powder. Pour in the milk and and beat to combine well.
Spoon into the prepared cupcake cases and bake for 12-15 minutes until a skewer inserted into the centre comes out clean.
Cool in the tin for five minutes before transferring to a wire rack to cool completely.
To prepare the frosting beat the butter and vanilla in a bowl until soft, sift in the icing sugar and beat well. Add the milk if the frosting is too stiff. Alternatively, place all the ingredients into an Optimum Thermocook and blend for a few seconds, scrape down, and blend again and again until the frosting is light and fluffy.
Frost your cupcakes and sprinkle with the chocolate crispies, if desired.
Notes
Recipe adapted from a chocolate and vanilla cupcake recipe found in Delicious Cupcakes Made Easy by Best Baking (2012)