Preheat the oven to 190 °C/375°F/Gas Mark 5 and fill a 12 cup muffin tin with paper cases.
Using a hand held electric whisk, wooden spoon or free standing mixer mix the 200 grams flour, 2 tsps baking powder, 40 grams cocoa, 80 grams butter, 280 grams sugar and pinch of salt on a slow speed until it is a sandy rubble and no lumps of butter are present.
Measure out the 240 mls of milk in a jug and then add the 2 eggs and mix well. if doing this by hand then switch to a whisk. Still on slow speed pour ¾ of the wet ingredients into the bowl until well incorporated. Then scrape down the sides of the bowl and add the rest of the liquid before turning up the speed to medium until the mixture is a smooth batter.
I put the batter into a jug to make it much easier to fill the paper cases about ¾ full. Scatter on a few chocolate chips/chunks in each cupcake. If you have time scatter a tbsp of flour onto the chocolate chips/chunks just to help them not sink to the bottom.
Bake for 18-20 minutes or until springy to the touch.Remove from the muffin tray and leave on a wire rack to cool completely.
Place the 400 grams of icing sugar, 100 grams of melted dark and 50 grams of milk chocolate, 1 tbsp of golden syrup and 150 mls of sour cream in a medium sized mixing bowl and whisk until smooth.
Slick onto the cupcakes once cool and top with mini eggs.
Apply To Chocolatey Grin.