Preheat the oven to 180ºc and line a 12 hole muffin tin with paper cases.
Sieve the flour, cornflour, spices and salt together.
Place the butter and sugar into a mixing bowl and mix until light, fluffy and pale in colour.
Add the eggs one at a time until each is incorporated before adding in the next.
Add in the vanilla extract followed by the molasses.
Once combined add in half of the flour mixing on low speed and once combined add in the milk.
Finish by adding in the remaining flour and mix until just combined or you will end up with tough cupcakes.
Spoon the batter into the cupcake cases and place in the oven for between 15-20 minutes until a toothpick comes out clean when inserted.
Once cooled make the buttercream.