Start by preparing the cupcakes. Preheat oven at 160C/320F. Add cupcake cases to a cupcake pan and set it aside for later.
Prepare dry ingredients: Add all-purpose flour, cocoa powder, baking soda, baking powder and mix until well combined. Set aside for later.
Prepare wet ingredients: Add unsalted butter to a bowl and whisk for 2 minutes. Then, add the caster sugar and whisk for another 3-5 minutes or until pale yellow.
Eggs: As you continue to whisk the mixture add one egg. Then whisk for a few minutes or until the egg disappears. Repeat this step for the remaining eggs.
Cupcake batter: Then, pour the wet ingredients into the dry ingredients, add milk and mix with a large spoon or spatula. Do not overmix the cupcake batter. Make sure there are still a few lumps.
Scoop about 2-3 tbsp of cake batter into each cupcake case and bake for 10-15 minutes.
Once the cupcakes are ready leave them to cool.